Following their dispiriting defeat to Manchester United before the international break, Arsene Wenger's Premier League leaders started brightly against their high-flying opponents, with Jack Wilshere and Aaron Ramsey both hitting the post.They led midway through the first half when Olivier Giroud capitalised on an inexplicable error from Boruc, who tried to dribble past the France international only to get himself in an awful tangle.
An impressive collective response was typical of a Southampton side who remain third in the table - for the time being - but Giroud completed his brace and made it 10 goals for the season from the penalty spot after Jose Fonte pulled back Per Mertesacker at an 85th-minute corner.
Southampton were dealt a blow ahead of kick-off, which was delayed by 15 minutes due to disruption on the Piccadilly line, with news that centre-back Dejan Lovren was ruled out due to illness. Jos Hooiveld came in for his first Premier League appearance of the season.
Theo Walcott returned to the Arsenal bench following two months out with an abdominal injury, while Mertesacker was back at the heart of defence following his midweek goalscoring heroics for Germany at Wembley.
Wilshere replaced the suspended Mathieu Flamini in midfield and almost opened the scoring after 10 minutes when his deft, lofted effort bounced back off the post and into Boruc's grateful arms.
The same upright was tested via Ramsey's audacious backheel from Mesut Ozil's cross - but Boruc's post could not save him after a moment of madness in the 22nd minute.
Upon receiving a routine backpass from Nathaniel Clyne, he loitered terribly before an embarrassing attempt to turn Giroud resulted in the Frenchman stroking the ball into an unguarded net.
Southampton forced Wojciech Szczesny into his first save of the match after 32 minutes when Mikel Arteta miscued a clearance and Adam Lallana's speculative left-footer was pushed over. The Arsenal goalkeeper then reacted superbly to thwart Jay Rodriguez's snap shot.
Luke Shaw struggled through much of the first half with a leg problem and was replaced by Steven Davis, with James Ward-Prowse reverting to right-back and Clyne filling Southampton's vacant left-back slot.
The reshuffle did not interrupt the visitors' momentum as they resumed brightly and Lallana thudded a drive into Szczesny's chest, meaning eyebrows were raised when the same player made way for Dani Osvaldo in the 52nd minute.
Having laboured under Southampton's trademark high press, Arsenal responded impressively and Ozil cleverly engineered space in the area to test Boruc at his near post.
Osvaldo called Szczesny into action at the end of a driving 74th minute run at the other end.
Walcott was afforded a rapturous reception on his introduction and might have given Arsenal breathing space when he fired wide on the break before Giroud ensured a four-point lead at the summit with his composed spot-kick.