Southampton moved to eighth in the Premier League as goals from Charlie Austin and Nathan Redmond punished Burnley’s poor second-half defending.
Austin broke the deadlock by poking home at the near post after Virgil van Dijk was allowed to head across the face of the goal from a corner.
Burnley’s defence was at fault again as Redmond beat Tom Heaton with a low strike from another corner.
Austin scored from the spot before a Sam Vokes penalty reduced the arrears.
Burnley’s defence has crumbled on a number of occasions in the second half of games this season, though it was thanks to a series of fine saves from Heaton that the score remained goalless for as long as it did.
The injury to influential midfielder Steven Defour before the break also hampered the visitors’ cause against a Southampton side who are now unbeaten in four league matches.
Chances galore for Southampton
Southampton, without first-choice full-backs Cedric Soares and Ryan Bertrand, suffered a further defensive set-back early on. Matt Targett, Bertrand’s replacement, injured his hamstring – but 21-year-old academy product Sam McQueen came on and performed well.
The Saints’ defence was organised despite the changes – although they did concede their first goal in 612 minutes of play – and the hosts created plenty of chances, troubling Heaton with 34 shots, the highest total by any team in a Premier League game this season.
Heaton has made more saves than any goalkeeper in the league – including 11 in this match. His most spectacular arguably came in the fourth minute as he dived low towards the bottom right corner to deny Austin.
But Burnley were caught out after the break when Van Dijk headed Dusan Tadic’s corner towards Austin, who was standing two yards from goal. The former Burnley player needed two attempts, with his first effort blocked on the line by Vokes before he poked in the rebound.
Moments after Heaton had made a brilliant save from Tadic, Burnley’s defence folded again as Steven Davis’ corner found the unmarked Redmond, who fired low beyond Heaton at his near post.
The visitors were rattled and it was no surprise that Southampton added to the scoreline, with Austin converting from the spot after Johann Berg Gudmundsson was deemed to have made contact with McQueen.
Southampton, particularly impressive in the closing stages as they charged forward in search of a fourth, came close to scoring again on a number of occasions with Davis, Jose Fonte, Jordy Clasie and Jay Rodriguez going close.
Should have Burnley have been awarded a first-half penalty?
Sean Dyche’s team were unlucky to lose to a controversial 94th-minute winner by Arsenal during their last Premier League outing, but they were unable to frustrate a free-flowing Southampton on this occasion and were fortunate not to suffer a heavier defeat.
The visitors had strong cause to appeal for a penalty in the first half after Gudmundsson was felled by Van Dijk but referee Mike Dean, standing yards in front of the challenge, ignored their pleas.
Dyche said after the match that it was a decision which could have changed the course of the match.
The Burnley manager argued that there was “minimal contact” between Gudmundsson and McQueen for Southampton’s penalty. However, it was also questionable whether Tadic’s brush with Ben Mee for the visitors’ spot-kick should have been punished.