diff --git a/litellm/llms/anthropic/experimental_pass_through/messages/handler.py b/litellm/llms/anthropic/experimental_pass_through/messages/handler.py
index a3ac465c463..8f82f37249a 100644
--- a/litellm/llms/anthropic/experimental_pass_through/messages/handler.py
+++ b/litellm/llms/anthropic/experimental_pass_through/messages/handler.py
@@ -6,8 +6,6 @@
 """
 
 import asyncio
-import contextvars
-from functools import partial
 from typing import (
     Any,
     AsyncIterator,
@@ -300,11 +298,9 @@ async def anthropic_messages(
                 **kwargs,
             )
 
-    loop = asyncio.get_event_loop()
     kwargs["is_async"] = True
 
-    func = partial(
-        anthropic_messages_handler,
+    response = anthropic_messages_handler(
         max_tokens=max_tokens,
         messages=messages,
         model=model,
@@ -330,14 +326,11 @@ async def anthropic_messages(
         _litellm_messages_presanitized=True,
         **kwargs,
     )
-    ctx = contextvars.copy_context()
-    func_with_context = partial(ctx.run, func)
-    init_response = await loop.run_in_executor(None, func_with_context)
-
-    if asyncio.iscoroutine(init_response):
-        response = await init_response
-    else:
-        response = init_response
+    # ``anthropic_messages_handler`` returns a coroutine on the async backend
+    # paths but a materialized response on the ``mock_response`` shortcut, so
+    # only await when there is something to await.
+    if asyncio.iscoroutine(response):
+        return await response
     return response
 
 
diff --git a/tests/test_litellm/llms/anthropic/experimental_pass_through/messages/test_anthropic_experimental_pass_through_messages_handler.py b/tests/test_litellm/llms/anthropic/experimental_pass_through/messages/test_anthropic_experimental_pass_through_messages_handler.py
index b1e1d789d74..d0efc4ba261 100644
--- a/tests/test_litellm/llms/anthropic/experimental_pass_through/messages/test_anthropic_experimental_pass_through_messages_handler.py
+++ b/tests/test_litellm/llms/anthropic/experimental_pass_through/messages/test_anthropic_experimental_pass_through_messages_handler.py
@@ -1,3 +1,4 @@
+import asyncio
 import json
 import os
 import sys
@@ -673,3 +674,33 @@ async def test_async_wrapper_sets_presanitized_and_sanitizes_once():
     assert spy.call_count == 1
     assert captured["presanitized"] is True
     assert [b["type"] for b in captured["messages"][0]["content"]] == ["tool_use"]
+
+
+@pytest.mark.asyncio
+async def test_aanthropic_messages_does_not_use_thread_executor():
+    """The async Anthropic /messages entry must dispatch the handler directly on
+    the running event loop, never through ``loop.run_in_executor``.
+
+    Mutation control: revert handler.py to
+    ``await loop.run_in_executor(None, func_with_context)`` and this test must
+    fail with AssertionError('thread hop fired').
+    """
+    from litellm.llms.anthropic.experimental_pass_through.messages import handler
+
+    loop = asyncio.get_running_loop()
+
+    def fail_on_thread_hop(*args, **kwargs):
+        raise AssertionError("thread hop fired")
+
+    with patch.object(loop, "run_in_executor", side_effect=fail_on_thread_hop):
+        response = await handler.anthropic_messages(
+            max_tokens=8,
+            messages=[{"role": "user", "content": "hi"}],
+            model="anthropic/claude-3-5-haiku-20241022",
+            custom_llm_provider="anthropic",
+            api_key="sk-test",
+            stream=False,
+            mock_response="pong",
+        )
+
+    assert response["content"][0]["text"] == "pong"