diff --git a/pageserver/src/tenant.rs b/pageserver/src/tenant.rs
index 3ed4621112..7fdd047c96 100644
--- a/pageserver/src/tenant.rs
+++ b/pageserver/src/tenant.rs
@@ -473,6 +473,14 @@ pub(crate) enum ShutdownError {
     AlreadyStopping,
 }
 
+struct DeletionGuard(OwnedMutexGuard<bool>);
+
+impl DeletionGuard {
+    fn is_deleted(&self) -> bool {
+        *self.0
+    }
+}
+
 impl Tenant {
     /// Yet another helper for timeline initialization.
     /// Contains the common part of `load_local_timeline` and `load_remote_timeline`.
@@ -1138,7 +1146,11 @@ impl Tenant {
                                 )
                                 .context("create_timeline_struct")?;
 
-                            let guard = Arc::clone(&timeline.delete_lock).lock_owned().await;
+                            let guard = DeletionGuard(
+                                Arc::clone(&timeline.delete_lock)
+                                    .try_lock_owned()
+                                    .expect("cannot happen because we're the only owner"),
+                            );
 
                             // Note: here we even skip populating layer map. Timeline is essentially uninitialized.
                             // RemoteTimelineClient is the only functioning part.
@@ -1549,6 +1561,7 @@ impl Tenant {
         &self,
         timeline_id: TimelineId,
         timeline: Arc<Timeline>,
+        guard: DeletionGuard,
     ) -> anyhow::Result<()> {
         {
             // Grab the layer_removal_cs lock, and actually perform the deletion.
@@ -1621,6 +1634,25 @@ impl Tenant {
             Err(anyhow::anyhow!("failpoint: timeline-delete-after-rm"))?
         });
 
+        if let Some(remote_client) = &timeline.remote_client {
+            remote_client.delete_all().await.context("delete_all")?
+        };
+
+        // Have a failpoint that can use the `pause` failpoint action.
+        // We don't want to block the executor thread, hence, spawn_blocking + await.
+        if cfg!(feature = "testing") {
+            tokio::task::spawn_blocking({
+                let current = tracing::Span::current();
+                move || {
+                    let _entered = current.entered();
+                    tracing::info!("at failpoint in_progress_delete");
+                    fail::fail_point!("in_progress_delete");
+                }
+            })
+            .await
+            .expect("spawn_blocking");
+        }
+
         {
             // Remove the timeline from the map.
             let mut timelines = self.timelines.lock().unwrap();
@@ -1641,12 +1673,7 @@ impl Tenant {
             drop(timelines);
         }
 
-        let remote_client = match &timeline.remote_client {
-            Some(remote_client) => remote_client,
-            None => return Ok(()),
-        };
-
-        remote_client.delete_all().await?;
+        drop(guard);
 
         Ok(())
     }
@@ -1694,23 +1721,18 @@ impl Tenant {
             timeline = Arc::clone(timeline_entry.get());
 
             // Prevent two tasks from trying to delete the timeline at the same time.
-            //
-            // XXX: We should perhaps return an HTTP "202 Accepted" to signal that the caller
-            // needs to poll until the operation has finished. But for now, we return an
-            // error, because the control plane knows to retry errors.
-
             delete_lock_guard =
-                Arc::clone(&timeline.delete_lock)
-                    .try_lock_owned()
-                    .map_err(|_| {
+                DeletionGuard(Arc::clone(&timeline.delete_lock).try_lock_owned().map_err(
+                    |_| {
                         DeleteTimelineError::Other(anyhow::anyhow!(
                             "timeline deletion is already in progress"
                         ))
-                    })?;
+                    },
+                )?);
 
             // If another task finished the deletion just before we acquired the lock,
             // return success.
-            if *delete_lock_guard {
+            if delete_lock_guard.is_deleted() {
                 return Ok(());
             }
 
@@ -1784,7 +1806,7 @@ impl Tenant {
         self: Arc<Self>,
         timeline_id: TimelineId,
         timeline: Arc<Timeline>,
-        _guard: OwnedMutexGuard<bool>,
+        guard: DeletionGuard,
     ) {
         let tenant_id = self.tenant_id;
         let timeline_clone = Arc::clone(&timeline);
@@ -1797,7 +1819,7 @@ impl Tenant {
             "timeline_delete",
             false,
             async move {
-                if let Err(err) = self.delete_timeline(timeline_id, timeline).await {
+                if let Err(err) = self.delete_timeline(timeline_id, timeline, guard).await {
                     error!("Error: {err:#}");
                     timeline_clone.set_broken(err.to_string())
                 };
diff --git a/pageserver/src/tenant/remote_timeline_client.rs b/pageserver/src/tenant/remote_timeline_client.rs
index 2c84c59dcb..8db2bc4eb2 100644
--- a/pageserver/src/tenant/remote_timeline_client.rs
+++ b/pageserver/src/tenant/remote_timeline_client.rs
@@ -753,22 +753,18 @@ impl RemoteTimelineClient {
 
         // Have a failpoint that can use the `pause` failpoint action.
         // We don't want to block the executor thread, hence, spawn_blocking + await.
-        #[cfg(feature = "testing")]
-        tokio::task::spawn_blocking({
-            let current = tracing::Span::current();
-            move || {
-                let _entered = current.entered();
-                tracing::info!(
-                    "at failpoint persist_index_part_with_deleted_flag_after_set_before_upload_pause"
-                );
-                fail::fail_point!(
-                    "persist_index_part_with_deleted_flag_after_set_before_upload_pause"
-                );
-            }
-        })
-        .await
-        .expect("spawn_blocking");
-
+        if cfg!(feature = "testing") {
+            tokio::task::spawn_blocking({
+                let current = tracing::Span::current();
+                move || {
+                    let _entered = current.entered();
+                    tracing::info!("at failpoint persist_deleted_index_part");
+                    fail::fail_point!("persist_deleted_index_part");
+                }
+            })
+            .await
+            .expect("spawn_blocking");
+        }
         upload::upload_index_part(
             self.conf,
             &self.storage_impl,
diff --git a/pageserver/src/tenant/timeline.rs b/pageserver/src/tenant/timeline.rs
index 855896c832..d42fdf5e55 100644
--- a/pageserver/src/tenant/timeline.rs
+++ b/pageserver/src/tenant/timeline.rs
@@ -3791,6 +3791,7 @@ impl Timeline {
     /// for example. The caller should hold `Tenant::gc_cs` lock to ensure
     /// that.
     ///
+    #[instrument(skip_all, fields(timline_id=%self.timeline_id))]
     pub(super) async fn update_gc_info(
         &self,
         retain_lsns: Vec<Lsn>,
diff --git a/test_runner/fixtures/neon_fixtures.py b/test_runner/fixtures/neon_fixtures.py
index a8610e24df..64c71d2a59 100644
--- a/test_runner/fixtures/neon_fixtures.py
+++ b/test_runner/fixtures/neon_fixtures.py
@@ -1631,6 +1631,8 @@ class NeonPageserver(PgProtocol):
             r".*ERROR.*ancestor timeline \S+ is being stopped",
             # this is expected given our collaborative shutdown approach for the UploadQueue
             ".*Compaction failed, retrying in .*: queue is in state Stopped.*",
+            # Pageserver timeline deletion should be polled until it gets 404, so ignore it globally
+            ".*Error processing HTTP request: NotFound: Timeline .* was not found",
         ]
 
     def start(
diff --git a/test_runner/fixtures/pageserver/http.py b/test_runner/fixtures/pageserver/http.py
index f258a3a24d..5c4f5177d0 100644
--- a/test_runner/fixtures/pageserver/http.py
+++ b/test_runner/fixtures/pageserver/http.py
@@ -342,6 +342,11 @@ class PageserverHttpClient(requests.Session):
         return res_json
 
     def timeline_delete(self, tenant_id: TenantId, timeline_id: TimelineId, **kwargs):
+        """
+        Note that deletion is not instant, it is scheduled and performed mostly in the background.
+        So if you need to wait for it to complete use `timeline_delete_wait_completed`.
+        For longer description consult with pageserver openapi spec.
+        """
         res = self.delete(
             f"http://localhost:{self.port}/v1/tenant/{tenant_id}/timeline/{timeline_id}", **kwargs
         )
diff --git a/test_runner/fixtures/pageserver/utils.py b/test_runner/fixtures/pageserver/utils.py
index 83880abc77..ad89ebad00 100644
--- a/test_runner/fixtures/pageserver/utils.py
+++ b/test_runner/fixtures/pageserver/utils.py
@@ -193,19 +193,30 @@ def wait_for_upload_queue_empty(
         time.sleep(0.2)
 
 
-def assert_timeline_detail_404(
+def wait_timeline_detail_404(
+    pageserver_http: PageserverHttpClient, tenant_id: TenantId, timeline_id: TimelineId
+):
+    last_exc = None
+    for _ in range(2):
+        time.sleep(0.250)
+        try:
+            data = pageserver_http.timeline_detail(tenant_id, timeline_id)
+            log.error(f"detail {data}")
+        except PageserverApiException as e:
+            log.debug(e)
+            if e.status_code == 404:
+                return
+
+            last_exc = e
+
+    raise last_exc or RuntimeError(f"Timeline wasnt deleted in time, state: {data['state']}")
+
+
+def timeline_delete_wait_completed(
     pageserver_http: PageserverHttpClient,
     tenant_id: TenantId,
     timeline_id: TimelineId,
+    **delete_args,
 ):
-    """Asserts that timeline_detail returns 404, or dumps the detail."""
-    try:
-        data = pageserver_http.timeline_detail(tenant_id, timeline_id)
-        log.error(f"detail {data}")
-    except PageserverApiException as e:
-        log.error(e)
-        if e.status_code == 404:
-            return
-        else:
-            raise
-    raise Exception("detail succeeded (it should return 404)")
+    pageserver_http.timeline_delete(tenant_id=tenant_id, timeline_id=timeline_id, **delete_args)
+    wait_timeline_detail_404(pageserver_http, tenant_id, timeline_id)
diff --git a/test_runner/regress/test_compatibility.py b/test_runner/regress/test_compatibility.py
index 2635dbd93c..61f86dc3ce 100644
--- a/test_runner/regress/test_compatibility.py
+++ b/test_runner/regress/test_compatibility.py
@@ -15,7 +15,11 @@ from fixtures.neon_fixtures import (
     PortDistributor,
 )
 from fixtures.pageserver.http import PageserverHttpClient
-from fixtures.pageserver.utils import wait_for_last_record_lsn, wait_for_upload
+from fixtures.pageserver.utils import (
+    timeline_delete_wait_completed,
+    wait_for_last_record_lsn,
+    wait_for_upload,
+)
 from fixtures.pg_version import PgVersion
 from fixtures.types import Lsn
 from pytest import FixtureRequest
@@ -417,7 +421,7 @@ def check_neon_works(
     )
 
     shutil.rmtree(repo_dir / "local_fs_remote_storage")
-    pageserver_http.timeline_delete(tenant_id, timeline_id)
+    timeline_delete_wait_completed(pageserver_http, tenant_id, timeline_id)
     pageserver_http.timeline_create(pg_version, tenant_id, timeline_id)
     pg_bin.run(
         ["pg_dumpall", f"--dbname={connstr}", f"--file={test_output_dir / 'dump-from-wal.sql'}"]
diff --git a/test_runner/regress/test_import.py b/test_runner/regress/test_import.py
index 5c3948b027..141c69b230 100644
--- a/test_runner/regress/test_import.py
+++ b/test_runner/regress/test_import.py
@@ -14,7 +14,11 @@ from fixtures.neon_fixtures import (
     NeonEnvBuilder,
     PgBin,
 )
-from fixtures.pageserver.utils import wait_for_last_record_lsn, wait_for_upload
+from fixtures.pageserver.utils import (
+    timeline_delete_wait_completed,
+    wait_for_last_record_lsn,
+    wait_for_upload,
+)
 from fixtures.types import Lsn, TenantId, TimelineId
 from fixtures.utils import subprocess_capture
 
@@ -151,7 +155,7 @@ def test_import_from_vanilla(test_output_dir, pg_bin, vanilla_pg, neon_env_build
         ".*files not bound to index_file.json, proceeding with their deletion.*"
     )
 
-    client.timeline_delete(tenant, timeline)
+    timeline_delete_wait_completed(client, tenant, timeline)
 
     # Importing correct backup works
     import_tar(base_tar, wal_tar)
diff --git a/test_runner/regress/test_remote_storage.py b/test_runner/regress/test_remote_storage.py
index 11ac9e2555..f2b954a822 100644
--- a/test_runner/regress/test_remote_storage.py
+++ b/test_runner/regress/test_remote_storage.py
@@ -20,7 +20,7 @@ from fixtures.neon_fixtures import (
 )
 from fixtures.pageserver.http import PageserverApiException, PageserverHttpClient
 from fixtures.pageserver.utils import (
-    assert_timeline_detail_404,
+    timeline_delete_wait_completed,
     wait_for_last_record_lsn,
     wait_for_upload,
     wait_until_tenant_active,
@@ -597,14 +597,11 @@ def test_timeline_deletion_with_files_stuck_in_upload_queue(
     env.pageserver.allowed_errors.append(
         ".* ERROR .*Error processing HTTP request: InternalServerError\\(timeline is Stopping"
     )
-    client.timeline_delete(tenant_id, timeline_id)
 
-    env.pageserver.allowed_errors.append(f".*Timeline {tenant_id}/{timeline_id} was not found.*")
     env.pageserver.allowed_errors.append(
         ".*files not bound to index_file.json, proceeding with their deletion.*"
     )
-
-    wait_until(2, 0.5, lambda: assert_timeline_detail_404(client, tenant_id, timeline_id))
+    timeline_delete_wait_completed(client, tenant_id, timeline_id)
 
     assert not timeline_path.exists()
 
diff --git a/test_runner/regress/test_tenant_size.py b/test_runner/regress/test_tenant_size.py
index e9dcd1e5cd..a0f9f854ed 100644
--- a/test_runner/regress/test_tenant_size.py
+++ b/test_runner/regress/test_tenant_size.py
@@ -11,6 +11,7 @@ from fixtures.neon_fixtures import (
     wait_for_wal_insert_lsn,
 )
 from fixtures.pageserver.http import PageserverHttpClient
+from fixtures.pageserver.utils import timeline_delete_wait_completed
 from fixtures.pg_version import PgVersion, xfail_on_postgres
 from fixtures.types import Lsn, TenantId, TimelineId
 
@@ -628,12 +629,12 @@ def test_get_tenant_size_with_multiple_branches(
     size_debug_file_before.write(size_debug)
 
     # teardown, delete branches, and the size should be going down
-    http_client.timeline_delete(tenant_id, first_branch_timeline_id)
+    timeline_delete_wait_completed(http_client, tenant_id, first_branch_timeline_id)
 
     size_after_deleting_first = http_client.tenant_size(tenant_id)
     assert size_after_deleting_first < size_after_thinning_branch
 
-    http_client.timeline_delete(tenant_id, second_branch_timeline_id)
+    timeline_delete_wait_completed(http_client, tenant_id, second_branch_timeline_id)
     size_after_deleting_second = http_client.tenant_size(tenant_id)
     assert size_after_deleting_second < size_after_deleting_first
 
diff --git a/test_runner/regress/test_tenant_tasks.py b/test_runner/regress/test_tenant_tasks.py
index 21e4af4127..75e5c2c91c 100644
--- a/test_runner/regress/test_tenant_tasks.py
+++ b/test_runner/regress/test_tenant_tasks.py
@@ -1,6 +1,10 @@
 from fixtures.log_helper import log
 from fixtures.neon_fixtures import NeonEnvBuilder
-from fixtures.pageserver.utils import assert_tenant_state, wait_until_tenant_active
+from fixtures.pageserver.utils import (
+    assert_tenant_state,
+    timeline_delete_wait_completed,
+    wait_until_tenant_active,
+)
 from fixtures.types import TenantId, TimelineId
 from fixtures.utils import wait_until
 
@@ -24,7 +28,7 @@ def test_tenant_tasks(neon_env_builder: NeonEnvBuilder):
     def delete_all_timelines(tenant: TenantId):
         timelines = [TimelineId(t["timeline_id"]) for t in client.timeline_list(tenant)]
         for t in timelines:
-            client.timeline_delete(tenant, t)
+            timeline_delete_wait_completed(client, tenant, t)
 
     # Create tenant, start compute
     tenant, _ = env.neon_cli.create_tenant()
diff --git a/test_runner/regress/test_tenants.py b/test_runner/regress/test_tenants.py
index 4a1d659be3..4dbfa8bc1f 100644
--- a/test_runner/regress/test_tenants.py
+++ b/test_runner/regress/test_tenants.py
@@ -21,6 +21,7 @@ from fixtures.neon_fixtures import (
     RemoteStorageKind,
     available_remote_storages,
 )
+from fixtures.pageserver.utils import timeline_delete_wait_completed
 from fixtures.types import Lsn, TenantId, TimelineId
 from fixtures.utils import wait_until
 from prometheus_client.samples import Sample
@@ -318,9 +319,10 @@ def test_pageserver_with_empty_tenants(
     client.tenant_create(tenant_with_empty_timelines)
     temp_timelines = client.timeline_list(tenant_with_empty_timelines)
     for temp_timeline in temp_timelines:
-        client.timeline_delete(
-            tenant_with_empty_timelines, TimelineId(temp_timeline["timeline_id"])
+        timeline_delete_wait_completed(
+            client, tenant_with_empty_timelines, TimelineId(temp_timeline["timeline_id"])
         )
+
     files_in_timelines_dir = sum(
         1
         for _p in Path.iterdir(
diff --git a/test_runner/regress/test_timeline_delete.py b/test_runner/regress/test_timeline_delete.py
index 28b15d03ca..ddd9ffd755 100644
--- a/test_runner/regress/test_timeline_delete.py
+++ b/test_runner/regress/test_timeline_delete.py
@@ -17,9 +17,10 @@ from fixtures.neon_fixtures import (
 )
 from fixtures.pageserver.http import PageserverApiException
 from fixtures.pageserver.utils import (
-    assert_timeline_detail_404,
+    timeline_delete_wait_completed,
     wait_for_last_record_lsn,
     wait_for_upload,
+    wait_timeline_detail_404,
     wait_until_tenant_active,
     wait_until_timeline_state,
 )
@@ -83,7 +84,7 @@ def test_timeline_delete(neon_simple_env: NeonEnv):
     wait_until(
         number_of_iterations=3,
         interval=0.2,
-        func=lambda: ps_http.timeline_delete(env.initial_tenant, leaf_timeline_id),
+        func=lambda: timeline_delete_wait_completed(ps_http, env.initial_tenant, leaf_timeline_id),
     )
 
     assert not timeline_path.exists()
@@ -94,16 +95,16 @@ def test_timeline_delete(neon_simple_env: NeonEnv):
         match=f"Timeline {env.initial_tenant}/{leaf_timeline_id} was not found",
     ) as exc:
         ps_http.timeline_detail(env.initial_tenant, leaf_timeline_id)
-
-        # FIXME leaves tenant without timelines, should we prevent deletion of root timeline?
-        wait_until(
-            number_of_iterations=3,
-            interval=0.2,
-            func=lambda: ps_http.timeline_delete(env.initial_tenant, parent_timeline_id),
-        )
-
     assert exc.value.status_code == 404
 
+    wait_until(
+        number_of_iterations=3,
+        interval=0.2,
+        func=lambda: timeline_delete_wait_completed(
+            ps_http, env.initial_tenant, parent_timeline_id
+        ),
+    )
+
     # Check that we didn't pick up the timeline again after restart.
     # See https://github.com/neondatabase/neon/issues/3560
     env.pageserver.stop(immediate=True)
@@ -143,7 +144,6 @@ def test_delete_timeline_post_rm_failure(
     ps_http.configure_failpoints((failpoint_name, "return"))
 
     ps_http.timeline_delete(env.initial_tenant, env.initial_timeline)
-
     timeline_info = wait_until_timeline_state(
         pageserver_http=ps_http,
         tenant_id=env.initial_tenant,
@@ -165,13 +165,7 @@ def test_delete_timeline_post_rm_failure(
 
     # this should succeed
     # this also checks that delete can be retried even when timeline is in Broken state
-    ps_http.timeline_delete(env.initial_tenant, env.initial_timeline, timeout=2)
-    with pytest.raises(PageserverApiException) as e:
-        ps_http.timeline_detail(env.initial_tenant, env.initial_timeline)
-
-    assert e.value.status_code == 404
-
-    env.pageserver.allowed_errors.append(f".*NotFound: Timeline.*{env.initial_timeline}.*")
+    timeline_delete_wait_completed(ps_http, env.initial_tenant, env.initial_timeline)
     env.pageserver.allowed_errors.append(
         f".*{env.initial_timeline}.*timeline directory not found, proceeding anyway.*"
     )
@@ -247,13 +241,7 @@ def test_timeline_resurrection_on_attach(
         pass
 
     # delete new timeline
-    ps_http.timeline_delete(tenant_id=tenant_id, timeline_id=branch_timeline_id)
-
-    env.pageserver.allowed_errors.append(
-        f".*Timeline {tenant_id}/{branch_timeline_id} was not found.*"
-    )
-
-    wait_until(2, 0.5, lambda: assert_timeline_detail_404(ps_http, tenant_id, branch_timeline_id))
+    timeline_delete_wait_completed(ps_http, tenant_id=tenant_id, timeline_id=branch_timeline_id)
 
     ##### Stop the pageserver instance, erase all its data
     env.endpoints.stop_all()
@@ -338,7 +326,6 @@ def test_timeline_delete_fail_before_local_delete(neon_env_builder: NeonEnvBuild
     )
 
     ps_http.timeline_delete(env.initial_tenant, leaf_timeline_id)
-
     timeline_info = wait_until_timeline_state(
         pageserver_http=ps_http,
         tenant_id=env.initial_tenant,
@@ -357,12 +344,15 @@ def test_timeline_delete_fail_before_local_delete(neon_env_builder: NeonEnvBuild
     # Wait for tenant to finish loading.
     wait_until_tenant_active(ps_http, tenant_id=env.initial_tenant, iterations=10, period=1)
 
-    env.pageserver.allowed_errors.append(
-        f".*Timeline {env.initial_tenant}/{leaf_timeline_id} was not found.*"
-    )
-    wait_until(
-        2, 0.5, lambda: assert_timeline_detail_404(ps_http, env.initial_tenant, leaf_timeline_id)
-    )
+    try:
+        data = ps_http.timeline_detail(env.initial_tenant, leaf_timeline_id)
+        log.debug(f"detail {data}")
+    except PageserverApiException as e:
+        log.debug(e)
+        if e.status_code != 404:
+            raise
+    else:
+        raise Exception("detail succeeded (it should return 404)")
 
     assert (
         not leaf_timeline_path.exists()
@@ -389,13 +379,8 @@ def test_timeline_delete_fail_before_local_delete(neon_env_builder: NeonEnvBuild
     assert env.initial_timeline is not None
 
     for timeline_id in (intermediate_timeline_id, env.initial_timeline):
-        ps_http.timeline_delete(env.initial_tenant, timeline_id)
-
-        env.pageserver.allowed_errors.append(
-            f".*Timeline {env.initial_tenant}/{timeline_id} was not found.*"
-        )
-        wait_until(
-            2, 0.5, lambda: assert_timeline_detail_404(ps_http, env.initial_tenant, timeline_id)
+        timeline_delete_wait_completed(
+            ps_http, tenant_id=env.initial_tenant, timeline_id=timeline_id
         )
 
         assert_prefix_empty(
@@ -419,23 +404,27 @@ def test_timeline_delete_fail_before_local_delete(neon_env_builder: NeonEnvBuild
     )
 
 
-def test_concurrent_timeline_delete_if_first_stuck_at_index_upload(
-    neon_env_builder: NeonEnvBuilder,
+@pytest.mark.parametrize(
+    "stuck_failpoint",
+    ["persist_deleted_index_part", "in_progress_delete"],
+)
+def test_concurrent_timeline_delete_stuck_on(
+    neon_env_builder: NeonEnvBuilder, stuck_failpoint: str
 ):
     """
-    If we're stuck uploading the index file with the is_delete flag,
-    eventually console will hand up and retry.
-    If we're still stuck at the retry time, ensure that the retry
-    fails with status 500, signalling to console that it should retry
-    later.
-    Ideally, timeline_delete should return 202 Accepted and require
-    console to poll for completion, but, that would require changing
-    the API contract.
+    If delete is stuck console will eventually retry deletion.
+    So we need to be sure that these requests wont interleave with each other.
+    In this tests we check two places where we can spend a lot of time.
+    This is a regression test because there was a bug when DeletionGuard wasnt propagated
+    to the background task.
+
+    Ensure that when retry comes if we're still stuck request will get an immediate error response,
+    signalling to console that it should retry later.
     """
 
     neon_env_builder.enable_remote_storage(
         remote_storage_kind=RemoteStorageKind.MOCK_S3,
-        test_name="test_concurrent_timeline_delete_if_first_stuck_at_index_upload",
+        test_name=f"concurrent_timeline_delete_stuck_on_{stuck_failpoint}",
     )
 
     env = neon_env_builder.init_start()
@@ -445,13 +434,14 @@ def test_concurrent_timeline_delete_if_first_stuck_at_index_upload(
     ps_http = env.pageserver.http_client()
 
     # make the first call sleep practically forever
-    failpoint_name = "persist_index_part_with_deleted_flag_after_set_before_upload_pause"
-    ps_http.configure_failpoints((failpoint_name, "pause"))
+    ps_http.configure_failpoints((stuck_failpoint, "pause"))
 
     def first_call(result_queue):
         try:
             log.info("first call start")
-            ps_http.timeline_delete(env.initial_tenant, child_timeline_id, timeout=10)
+            timeline_delete_wait_completed(
+                ps_http, env.initial_tenant, child_timeline_id, timeout=10
+            )
             log.info("first call success")
             result_queue.put("success")
         except Exception:
@@ -466,7 +456,7 @@ def test_concurrent_timeline_delete_if_first_stuck_at_index_upload(
 
         def first_call_hit_failpoint():
             assert env.pageserver.log_contains(
-                f".*{child_timeline_id}.*at failpoint {failpoint_name}"
+                f".*{child_timeline_id}.*at failpoint {stuck_failpoint}"
             )
 
         wait_until(50, 0.1, first_call_hit_failpoint)
@@ -484,8 +474,12 @@ def test_concurrent_timeline_delete_if_first_stuck_at_index_upload(
         )
         log.info("second call failed as expected")
 
+        # ensure it is not 404 and stopping
+        detail = ps_http.timeline_detail(env.initial_tenant, child_timeline_id)
+        assert detail["state"] == "Stopping"
+
         # by now we know that the second call failed, let's ensure the first call will finish
-        ps_http.configure_failpoints((failpoint_name, "off"))
+        ps_http.configure_failpoints((stuck_failpoint, "off"))
 
         result = first_call_result.get()
         assert result == "success"
@@ -498,8 +492,10 @@ def test_concurrent_timeline_delete_if_first_stuck_at_index_upload(
 
 def test_delete_timeline_client_hangup(neon_env_builder: NeonEnvBuilder):
     """
-    If the client hangs up before we start the index part upload but after we mark it
+    If the client hangs up before we start the index part upload but after deletion is scheduled
+    we mark it
     deleted in local memory, a subsequent delete_timeline call should be able to do
+
     another delete timeline operation.
 
     This tests cancel safety up to the given failpoint.
@@ -515,12 +511,18 @@ def test_delete_timeline_client_hangup(neon_env_builder: NeonEnvBuilder):
 
     ps_http = env.pageserver.http_client()
 
-    failpoint_name = "persist_index_part_with_deleted_flag_after_set_before_upload_pause"
+    failpoint_name = "persist_deleted_index_part"
     ps_http.configure_failpoints((failpoint_name, "pause"))
 
     with pytest.raises(requests.exceptions.Timeout):
         ps_http.timeline_delete(env.initial_tenant, child_timeline_id, timeout=2)
 
+    env.pageserver.allowed_errors.append(
+        f".*{child_timeline_id}.*timeline deletion is already in progress.*"
+    )
+    with pytest.raises(PageserverApiException, match="timeline deletion is already in progress"):
+        ps_http.timeline_delete(env.initial_tenant, child_timeline_id, timeout=2)
+
     # make sure the timeout was due to the failpoint
     at_failpoint_log_message = f".*{child_timeline_id}.*at failpoint {failpoint_name}.*"
 
@@ -552,12 +554,7 @@ def test_delete_timeline_client_hangup(neon_env_builder: NeonEnvBuilder):
     wait_until(50, 0.1, first_request_finished)
 
     # check that the timeline is gone
-    notfound_message = f"Timeline {env.initial_tenant}/{child_timeline_id} was not found"
-    env.pageserver.allowed_errors.append(".*" + notfound_message)
-    with pytest.raises(PageserverApiException, match=notfound_message) as exc:
-        ps_http.timeline_detail(env.initial_tenant, child_timeline_id)
-
-    assert exc.value.status_code == 404
+    wait_timeline_detail_404(ps_http, env.initial_tenant, child_timeline_id)
 
 
 @pytest.mark.parametrize(
@@ -616,12 +613,7 @@ def test_timeline_delete_works_for_remote_smoke(
     for timeline_id in reversed(timeline_ids):
         # note that we need to finish previous deletion before scheduling next one
         # otherwise we can get an "HasChildren" error if deletion is not fast enough (real_s3)
-        ps_http.timeline_delete(tenant_id=tenant_id, timeline_id=timeline_id)
-
-        env.pageserver.allowed_errors.append(
-            f".*Timeline {env.initial_tenant}/{timeline_id} was not found.*"
-        )
-        wait_until(2, 0.5, lambda: assert_timeline_detail_404(ps_http, tenant_id, timeline_id))
+        timeline_delete_wait_completed(ps_http, tenant_id=tenant_id, timeline_id=timeline_id)
 
         assert_prefix_empty(
             neon_env_builder,
diff --git a/test_runner/regress/test_timeline_size.py b/test_runner/regress/test_timeline_size.py
index 1460172afe..5bdbc18927 100644
--- a/test_runner/regress/test_timeline_size.py
+++ b/test_runner/regress/test_timeline_size.py
@@ -24,6 +24,7 @@ from fixtures.neon_fixtures import (
 from fixtures.pageserver.http import PageserverApiException, PageserverHttpClient
 from fixtures.pageserver.utils import (
     assert_tenant_state,
+    timeline_delete_wait_completed,
     wait_for_upload_queue_empty,
     wait_until_tenant_active,
 )
@@ -272,7 +273,7 @@ def test_timeline_initial_logical_size_calculation_cancellation(
             if deletion_method == "tenant_detach":
                 client.tenant_detach(tenant_id)
             elif deletion_method == "timeline_delete":
-                client.timeline_delete(tenant_id, timeline_id)
+                timeline_delete_wait_completed(client, tenant_id, timeline_id)
             delete_timeline_success.put(True)
         except PageserverApiException:
             delete_timeline_success.put(False)
diff --git a/test_runner/regress/test_wal_acceptor.py b/test_runner/regress/test_wal_acceptor.py
index 8b595596cb..a837501678 100644
--- a/test_runner/regress/test_wal_acceptor.py
+++ b/test_runner/regress/test_wal_acceptor.py
@@ -31,7 +31,11 @@ from fixtures.neon_fixtures import (
     SafekeeperPort,
     available_remote_storages,
 )
-from fixtures.pageserver.utils import wait_for_last_record_lsn, wait_for_upload
+from fixtures.pageserver.utils import (
+    timeline_delete_wait_completed,
+    wait_for_last_record_lsn,
+    wait_for_upload,
+)
 from fixtures.pg_version import PgVersion
 from fixtures.types import Lsn, TenantId, TimelineId
 from fixtures.utils import get_dir_size, query_scalar, start_in_background
@@ -548,15 +552,15 @@ def test_s3_wal_replay(neon_env_builder: NeonEnvBuilder, remote_storage_kind: Re
                     f"sk_id={sk.id} to flush {last_lsn}",
                 )
 
-    ps_cli = env.pageserver.http_client()
-    pageserver_lsn = Lsn(ps_cli.timeline_detail(tenant_id, timeline_id)["last_record_lsn"])
+    ps_http = env.pageserver.http_client()
+    pageserver_lsn = Lsn(ps_http.timeline_detail(tenant_id, timeline_id)["last_record_lsn"])
     lag = last_lsn - pageserver_lsn
     log.info(
         f"Pageserver last_record_lsn={pageserver_lsn}; flush_lsn={last_lsn}; lag before replay is {lag / 1024}kb"
     )
 
     endpoint.stop_and_destroy()
-    ps_cli.timeline_delete(tenant_id, timeline_id)
+    timeline_delete_wait_completed(ps_http, tenant_id, timeline_id)
 
     # Also delete and manually create timeline on safekeepers -- this tests
     # scenario of manual recovery on different set of safekeepers.
@@ -583,7 +587,7 @@ def test_s3_wal_replay(neon_env_builder: NeonEnvBuilder, remote_storage_kind: Re
         shutil.copy(f_partial_saved, f_partial_path)
 
     # recreate timeline on pageserver from scratch
-    ps_cli.timeline_create(
+    ps_http.timeline_create(
         pg_version=PgVersion(pg_version),
         tenant_id=tenant_id,
         new_timeline_id=timeline_id,
@@ -598,7 +602,7 @@ def test_s3_wal_replay(neon_env_builder: NeonEnvBuilder, remote_storage_kind: Re
         if elapsed > wait_lsn_timeout:
             raise RuntimeError("Timed out waiting for WAL redo")
 
-        tenant_status = ps_cli.tenant_status(tenant_id)
+        tenant_status = ps_http.tenant_status(tenant_id)
         if tenant_status["state"]["slug"] == "Loading":
             log.debug(f"Tenant {tenant_id} is still loading, retrying")
         else: