Robin van Persie struck twice in the dying moments to complete his first Manchester United hat-trick and ensure Sir Alex Ferguson's side marked the manager's 1000th English league game with a 3-2 victory over Southampton on Sunday.

Ferguson appeared destined for disappointment on his landmark occasion when United trailed with three minutes of normal time remaining at St Mary's.

But van Persie - who had earlier cancelled out Rickie Lambert's 16th minute opener and missed a penalty after Southampton had again gone ahead through Morgan Schneiderlin - equalised from close range in the 87th minute after Rio Ferdinand's header had struck the post.

Then with the game in stoppage-time, the Holland international met Nani's corner with a near post header that brought the striker's 100th Premier League goal and secured a fortunate win for Ferguson's team.

Van Persie's late intervention was agonising for a Southampton side who had performed well and dominated periods of the game but are still looking for their first point of the season.

"It was a good feeling afterwards," van Persie told Sky Sports. "I'm very disappointed with the penalty. When that happens at 2-1 down, you can't take a penalty like that. Something went wrong big time.

"I have to say a big thank you to Paul Scholes. Every single pass he hit was the right one. It was unbelievable. He is man of the match for me."

Ferguson provided a reminder of his ruthless streak before kick-off when he revealed goalkeeper David De Gea had been dropped as punishment for his error in the 3-2 victory over Fulham, with Anders Lindegaard recalled at the Spaniard's expense.

In front of Lindegaard, Ferdinand and Nemanja Vidic were reunited in central defence for the first time since last December.

But despite their combined wealth of experience, it quickly became clear Lambert was capable of troubling the United backline, with Ferdinand in particular suffering a testing opening 45 minutes.

The visitors started brightly enough with van Persie producing two moments of quality, a neat backheel followed by an expert chest and volley, that suggested it could be a long afternoon for Nigel Adkins' side.

But having weathered United's confident opening spell, Southampton began to assert themselves.

A clever corner routine created an opening for Adam Lallana that the Saints captain fired wide moments before Lambert claimed his second league goal of the season with 16 minutes gone.

United were guilty of providing Southampton with the opportunity to build the forward move with Tom Cleverley's misplaced pass allowing Schneiderlin to steal possession and drive forward, moving the ball on to Steven Davis who found Jason Puncheon on the right.

Puncheon cut inside and sent a left foot cross towards Lambert at the far post and the forward was far too powerful for his marker Rafael da Silva, rising to head home past Lindegaard.

However, van Persie produced an outstanding finish for the 23rd minute equaliser, volleying home from a tight angle after being picked out by Antonio Valencia's deep cross and profiting from right back Nathaniel Clyne's slip.

Southampton refused to be intimidated and were rewarded for their adventure 11 minutes after the restart when Schneiderlin headed the home side into the lead for a second time.

This time Lambert turned provider, crossing for the midfielder who profited from yet another slip, this time by Patrice Evra, to send a free header well clear of Lindegaard.

With more composure, Southampton might have added a third but they conceded a penalty when Jos Hooiveld clattered through the back of van Persie in the 69th minute.

The United striker stepped up to take the spot-kick but appeared to be caught in two minds as he sent a poorly struck chip to Kelvin Davis's right and the keeper saved easily.

That brought redemption for Davis whose poor kick had gifted Nani possession immediately before van Persie was fouled.

But there would be further twists as van Persie went from zero to hero with a close-range equaliser and then a clinical stoppage-time header to steal the points.