United turned defeat into an astonishing victory with two late goals by Robin van Persie completing a remarkable hat-trick by the Dutchman in Sir Alex Ferguson's 1,000th league game as Reds manager.
A second defeat in three games of the new season looked on the cards but the summer signing from Arsenal made up for missing a second-half penalty in sensational fashion. Van Persie cancelled out Rickie Lambert's opener with a clinical finish but, after Morgan Schneiderlin netted a second-half header, the star striker wasted a potential lifeline after 69 minutes when his weak penalty was saved by Kelvin Davis.
The Reds pressed from the outset and initially looked a cut above the newly-promoted Saints with the classy van Persie prodding a volley wide after expertly controlling a Michael Carrick pass on his chest. However, Nigel Adkins’ side grew in stature and almost caught the defence out when a well-worked corner led to Adam Lallana dragging a shot wide. Schneiderlin blazed over from long range and the warning signs were not heeded by United.
Schneiderlin won the ball from Shinji Kagawa in midfield and, when it was switched from Steven Davis to Jason Puncheon, his deep cross set the alarm bells ringing. Lambert had pulled onto Rafael at the far post and comfortably outjumped the Brazilian to nod past Anders Lindegaard.
A response was required and Kagawa almost supplied it with a low drive that was blocked by Kelvin Davis before van Persie illustrated his striking prowess. Danny Welbeck fed Antonio Valencia on the right and, once van Persie had chested down the cross as Nathaniel Clyne slipped, there was only ever going to be one outcome. A flash of the famous left foot saw the ball fly into the corner of the net, via a touch off Davis, to register the Dutchman’s second goal in consecutive games.