The match began at frenetic pace, Adam Lallana going close inside five minutes for Saints as his volley was cleared off the line by Peter Clarke, while Alan Lee struck a post for the visitors with a point-blank header after 10 minutes.
The breakthrough came six minutes later when Terriers midfielder Gary Roberts' fizzing left-footed cross was met powerfully by Lee Novak, who headed clinically past a sprawling Kelvin Davis.
Yet Saints were level just 12 minutes later, Rickie Lambert latching onto a Dan Harding throw-in to lash home from 18 yards. And three minutes later the home side were ahead, livewire winger Alex Chamberlain jinking into space inside the Huddersfield box before coolly slotting into the bottom left corner.
Southampton continued to dominate into the second period and deservedly added a third in the simplest of fashions, Radhi Jaidi rising like a salmon out of water to head home a pin-point Lallana free-kick after 51 minutes.
And the rout was complete 20 minutes from time when on-loan midfielder Richard Chaplow fired home a left-footed drive to hand the dominant Saints all three points.