diff --git a/bigquery/storage/managedwriter/managed_stream.go b/bigquery/storage/managedwriter/managed_stream.go
index 6a18dd0f574..4988280527f 100644
--- a/bigquery/storage/managedwriter/managed_stream.go
+++ b/bigquery/storage/managedwriter/managed_stream.go
@@ -262,20 +262,28 @@ func (ms *ManagedStream) openWithRetry() (storagepb.BigQueryWrite_AppendRowsClie
 
 // lockingAppend handles a single append attempt.  When successful, it returns the number of rows
 // in the request for metrics tracking.
-func (ms *ManagedStream) lockingAppend(pw *pendingWrite) (int64, error) {
+func (ms *ManagedStream) lockingAppend(pw *pendingWrite) error {
 
 	// Don't both calling/retrying if this append's context is already expired.
 	if err := pw.reqCtx.Err(); err != nil {
-		return 0, err
+		return err
 	}
 
+	// we use this to record stats if needed after we unlock on defer.
+	var statsOnExit func()
+
 	// critical section:  Things that need to happen inside the critical section:
 	//
 	// * Getting the stream connection (in case of reconnects)
 	// * Issuing the append request
 	// * Adding the pending write to the channel to keep ordering correct on response
 	ms.mu.Lock()
-	defer ms.mu.Unlock()
+	defer func() {
+		ms.mu.Unlock()
+		if statsOnExit != nil {
+			statsOnExit()
+		}
+	}()
 
 	var arc *storagepb.BigQueryWrite_AppendRowsClient
 	var ch chan *pendingWrite
@@ -290,7 +298,7 @@ func (ms *ManagedStream) lockingAppend(pw *pendingWrite) (int64, error) {
 	}
 	arc, ch, err = ms.getStream(arc, reconnect)
 	if err != nil {
-		return 0, err
+		return err
 	}
 
 	// Resolve the special work for the first append on a stream.
@@ -318,13 +326,19 @@ func (ms *ManagedStream) lockingAppend(pw *pendingWrite) (int64, error) {
 		if shouldReconnect(err) {
 			ms.reconnect = true
 		}
-		return 0, err
+		return err
 	}
 	// Compute numRows, once we pass ownership to the channel the request may be
 	// cleared.
 	numRows := int64(len(pw.request.GetProtoRows().Rows.GetSerializedRows()))
+	statsOnExit = func() {
+		// these will get recorded once we exit the critical section.
+		recordStat(ms.ctx, AppendRequestRows, numRows)
+		recordStat(ms.ctx, AppendRequests, 1)
+		recordStat(ms.ctx, AppendRequestBytes, int64(pw.reqSize))
+	}
 	ch <- pw
-	return numRows, nil
+	return nil
 }
 
 // appendWithRetry handles the details of adding sending an append request on a stream.  Appends are sent on a long
@@ -343,7 +357,7 @@ func (ms *ManagedStream) appendWithRetry(pw *pendingWrite, opts ...gax.CallOptio
 	}
 
 	for {
-		numRows, appendErr := ms.lockingAppend(pw)
+		appendErr := ms.lockingAppend(pw)
 		if appendErr != nil {
 			// Append yielded an error.  Retry by continuing or return.
 			status := grpcstatus.Convert(appendErr)
@@ -362,9 +376,6 @@ func (ms *ManagedStream) appendWithRetry(pw *pendingWrite, opts ...gax.CallOptio
 			pw.markDone(nil, appendErr, ms.fc)
 			return appendErr
 		}
-		recordStat(ms.ctx, AppendRequests, 1)
-		recordStat(ms.ctx, AppendRequestBytes, int64(pw.reqSize))
-		recordStat(ms.ctx, AppendRequestRows, numRows)
 		return nil
 	}
 }