Arsenal's early relentless paid off after just 10 minutes when Jos Hooiveld deflected the ball into the back of his own net after goalkeeper Kelvin Davis had parried away Kieran Gibbs' angled attempt. The left-back was fed by a great pass from Lukas Podolski who barnstormed past a group of Saints defenders before dishing off for Gibbs who forced Davis into a save with the ball then popping in off Hooiveld.
Arsenal kept coming and were rewarded with a second goal just after the half-hour mark when Podolski netted his second goal for the club with a brilliant curling 25-yard free-kick which he managed to get over the wall and in under Davis' crossbar.
Less than five minutes later, the Gunners were three to the good when Gervinho got on the end of a brilliant Mikel Arteta chipped pass to hammer home at Davis' near post with the Saints gloveman unable to get anything on the ball.
The Gunners were then in dreamland when Gervinho released Gibbs down the left with his cross deflected past Davis by Nathaniel Clyne to make it 4-0 prior to the break.
Southampton managed to get one back late in the first half when Wojciech Szczesny, back in the line-up after a rib problem, spilled Jason Puncheon's cross from the right for an unmarked Danny Fox to fire into the roof of the net.
The Saints pressed hard for a period in the second half which troubled the Gunners but the home side were able to find a fifth goal when substitute Aaron Ramsey's shot deflected off the post and into the path of Gervinho who couldn't miss from a yard out for his second goal today and second since December.
Arsenal weren't done there and managed a sixth when substitute Theo Walcott finished unerringly against his former club with his left foot after Thomas Vermaelen's fierce attempt was kept out by a busy Davis.
Podolski, who seems to have found his feet for his new club, tested Davis with a long range bomb in the second minute before the Saints keeper made a neat diving save to deny Per Mertesacker's header to make up for his scuffed clearance from a corner.
Rickie Lambert had a great chance to get another back for the Saints when they were 4-1 down in the 57th minute but the big striker screwed his angled attempt wide under extreme pressure from Szczesny.
Late in the game, Puncheon was played in by an impressive James Ward-Prowse but Szczesny was able to stick out a leg and keep the winger's goalbound shot out of the net.
In the end, there was little to write home about for Nigel Adkins' men who are yet to record a point from four games with a massive 14 goals conceded as Arsene Wenger's Arsenal moved to third after their second win on the trot with a goal difference of seven after two scoreless draws to start the season.
Emirates Stadium, London - 60,097
ARS - nil SOU - nil