Southampton made it three wins from three league matches following a seven-goal thriller at Ipswich.
Rickie Lambert opened the scoring with a 12-yard finish and then curled his second into the bottom corner.
David Connolly converted Guly Do Prado's square ball to make it 3-0 before Town reduced the arrears thanks to strikes from Keith Andrews and substitute Jay Emmanuel-Thomas.
The pacy Adam Lallana ended the comeback with two low efforts late on.
Nigel Adkins's Saints have now scored nine goals in three matches and have won their last nine matches stretching back to last season.
The visitors created other chances, with Lallana dragging his shot wide inside the first four minutes while Guly was also fractions off target with a fierce strike.
Ipswich also had more opportunities to score. Midfielder Lee Bowyer picked up a lofted ball before firing a shot that was saved by former Town stopper Kelvin Davis.
Aaron Cresswell came close to opening his Ipswich account but sent his left-footed strike wide.
Ipswich are 16th having lost two and won one of their three league fixtures.