diff --git a/tests/unit/vertexai/genai/test_evals.py b/tests/unit/vertexai/genai/test_evals.py
index 5e7b03f57f..2c6442818d 100644
--- a/tests/unit/vertexai/genai/test_evals.py
+++ b/tests/unit/vertexai/genai/test_evals.py
@@ -1070,9 +1070,7 @@ def test_run_inference_with_agent_engine_and_session_inputs_dict(
         )
 
         mock_agent_engine = mock.Mock()
-        mock_agent_engine.async_create_session = mock.AsyncMock(
-            return_value={"id": "session1"}
-        )
+        mock_agent_engine.create_session.return_value = {"id": "session1"}
         stream_query_return_value = [
             {
                 "id": "1",
@@ -1088,13 +1086,7 @@ def test_run_inference_with_agent_engine_and_session_inputs_dict(
             },
         ]
 
-        async def _async_iterator(iterable):
-            for item in iterable:
-                yield item
-
-        mock_agent_engine.async_stream_query.return_value = _async_iterator(
-            stream_query_return_value
-        )
+        mock_agent_engine.stream_query.return_value = iter(stream_query_return_value)
         mock_vertexai_client.return_value.agent_engines.get.return_value = (
             mock_agent_engine
         )
@@ -1108,10 +1100,10 @@ async def _async_iterator(iterable):
         mock_vertexai_client.return_value.agent_engines.get.assert_called_once_with(
             name="projects/test-project/locations/us-central1/reasoningEngines/123"
         )
-        mock_agent_engine.async_create_session.assert_called_once_with(
+        mock_agent_engine.create_session.assert_called_once_with(
             user_id="123", state={"a": "1"}
         )
-        mock_agent_engine.async_stream_query.assert_called_once_with(
+        mock_agent_engine.stream_query.assert_called_once_with(
             user_id="123", session_id="session1", message="agent prompt"
         )
 
@@ -1162,9 +1154,7 @@ def test_run_inference_with_agent_engine_and_session_inputs_literal_string(
         )
 
         mock_agent_engine = mock.Mock()
-        mock_agent_engine.async_create_session = mock.AsyncMock(
-            return_value={"id": "session1"}
-        )
+        mock_agent_engine.create_session.return_value = {"id": "session1"}
         stream_query_return_value = [
             {
                 "id": "1",
@@ -1180,13 +1170,7 @@ def test_run_inference_with_agent_engine_and_session_inputs_literal_string(
             },
         ]
 
-        async def _async_iterator(iterable):
-            for item in iterable:
-                yield item
-
-        mock_agent_engine.async_stream_query.return_value = _async_iterator(
-            stream_query_return_value
-        )
+        mock_agent_engine.stream_query.return_value = iter(stream_query_return_value)
         mock_vertexai_client.return_value.agent_engines.get.return_value = (
             mock_agent_engine
         )
@@ -1200,10 +1184,10 @@ async def _async_iterator(iterable):
         mock_vertexai_client.return_value.agent_engines.get.assert_called_once_with(
             name="projects/test-project/locations/us-central1/reasoningEngines/123"
         )
-        mock_agent_engine.async_create_session.assert_called_once_with(
+        mock_agent_engine.create_session.assert_called_once_with(
             user_id="123", state={"a": "1"}
         )
-        mock_agent_engine.async_stream_query.assert_called_once_with(
+        mock_agent_engine.stream_query.assert_called_once_with(
             user_id="123", session_id="session1", message="agent prompt"
         )
 
diff --git a/vertexai/_genai/_evals_common.py b/vertexai/_genai/_evals_common.py
index 8388784272..341ae88a7f 100644
--- a/vertexai/_genai/_evals_common.py
+++ b/vertexai/_genai/_evals_common.py
@@ -278,12 +278,10 @@ def agent_run_wrapper(
                             and type(agent_engine).__name__ == "AgentEngine"
                         ):
                             agent_engine_instance = agent_engine
-                        return asyncio.run(
-                            inference_fn_arg(
-                                row=row_arg,
-                                contents=contents_arg,
-                                agent_engine=agent_engine_instance,
-                            )
+                        return inference_fn_arg(
+                            row=row_arg,
+                            contents=contents_arg,
+                            agent_engine=agent_engine_instance,
                         )
 
                     future = executor.submit(
@@ -1265,7 +1263,7 @@ def _run_agent(
     )
 
 
-async def _execute_agent_run_with_retry(
+def _execute_agent_run_with_retry(
     row: pd.Series,
     contents: Union[genai_types.ContentListUnion, genai_types.ContentListUnionDict],
     agent_engine: types.AgentEngine,
@@ -1287,7 +1285,7 @@ async def _execute_agent_run_with_retry(
             )
         user_id = session_inputs.user_id
         session_state = session_inputs.state
-        session = await agent_engine.async_create_session(
+        session = agent_engine.create_session(
             user_id=user_id,
             state=session_state,
         )
@@ -1298,7 +1296,7 @@ async def _execute_agent_run_with_retry(
     for attempt in range(max_retries):
         try:
             responses = []
-            async for event in agent_engine.async_stream_query(
+            for event in agent_engine.stream_query(
                 user_id=user_id,
                 session_id=session["id"],
                 message=contents,
@@ -1317,7 +1315,7 @@ async def _execute_agent_run_with_retry(
             )
             if attempt == max_retries - 1:
                 return {"error": f"Resource exhausted after retries: {e}"}
-            await asyncio.sleep(2**attempt)
+            time.sleep(2**attempt)
         except Exception as e:  # pylint: disable=broad-exception-caught
             logger.error(
                 "Unexpected error during generate_content on attempt %d/%d: %s",
@@ -1328,7 +1326,7 @@ async def _execute_agent_run_with_retry(
 
             if attempt == max_retries - 1:
                 return {"error": f"Failed after retries: {e}"}
-            await asyncio.sleep(1)
+            time.sleep(1)
     return {"error": f"Failed to get agent run results after {max_retries} retries"}