Swansea, by contrast, were abject and remain without a win since the opening day of the season.
They were without defender Neil Taylor, conspicuous by his absence following his public fall-out with manager Francesco Guidolin, who subbed him before half-time against Chelsea last weekend.
But it was in attack where they laboured, with summer signing Fernando Llorente never looking like opening his goal account.
Southampton bossed proceedings from the off and were almost gifted the lead when keeper Lukasz Fabianski spilled a shot from Shane Long.
Steven Davis and Dusan Tadic charged in to tuck away the follow-up only to get in each other’s way and put the ball behind, but fortunately for the duo an offside flag spared their blushes.
Long thought he should have been awarded a penalty after going down under Ferderico Fernandez’s challenge in the area, but referee Mike Jones saw it differently and booked the Saints forward for a dive.