Robin van Persie's double gave Manchester United a somewhat fortuitous win against Southampton at St. Mary's on Monday night.

The Dutchman struck in both halves as United were let off by the home side on a number of occasions, after a series of errors gifted Ronald Koeman's side a host of great chances. Graziano Pelle did profit from one mistake to level the match at the break, but United ran out as winners to jump to third in the Premier League.

Louis van Gaal reverted to a back three to compensate for United's defensive absentees and both teams did their best to settle in the opening minutes. But Southampton's high energy pressing made it difficult for the visitors to gain a foothold in the game and Shane Long - deployed on the right side - showed early signs that he could give Ashley Young a problem or two.

But out of nothing, it was United who took the lead, and they had Saints captain Jose Fonte to thank. As Wayne Rooney attempted to run at him but put too much on the ball, Fonte looked to pass the ball back to Fraser Forster in goal - only for Robin van Persie to steal in on the soft backpass and slot it home.

For United, who lost Chris Smalling to yet another injury minutes later, fell under much heavier pressure as the half progressed - though much of it was through their own mistakes. Spaces were appearing at the back, and Sadio Mane should have capitalised on a mistake by Paddy McNair. The former Salzburg man had several opportunities to shoot at goal as he attacked United's abject defenders, but was eventually crowded out after making his way into the penalty area.

Southampton v Manchester United - Premier League

The pressure though was to eventually tell. A poor pass from Marouane Fellaini in midfield led to an attack from the home side, and after the Belgian missed a clearing header as he got back to defend, the ball found its way to Graziano Pelle who smashed in his 7th goal of the season.

United's half was deteriorating rapidly, and they nearly fell behind after more poor defending from young Northern Irishman McNair. His missed clearance in the box found its way to Shane Long, who snatched at his chance and hit it over the bar. The uncompromising van Gaal removed the 19-year-old for Ander Herrera in an attempt to stop a worrying, yet familiar rot prior to the break.

If the visitors were expected to buck up their ideas after the interval, there were no signs of it in the early minutes. Long should have put the Saints in front after finding himself with a free header at the far post, but he could only direct his attempt at David de Gea.

Eventually - and slowly - United were to get a grasp of possession. It still didn't make their defence anywhere near water tight, but if they could manage to keep the ball a little better, that was at least some of the job made easier from their point of view. The frequency of possession lost in key areas began to wane, and but for a few scares, van Gaal's side looked steadier.

Southampton v Manchester United - Premier League

United forced a free kick on the left hand touchline, and captain Wayne Rooney came across to take it with 20 minutes left on the clock. His superb whipped delivery ended up finding his strike partner van Persie at the back post, who again bundled the ball through Foster's legs to restore United's lead.

But for a decent stop from De Gea from Pelle's attempt after the goal, United had somehow forced themselves on top. Getting back in numbers, the visitors were having better luck with restricting dangerous Southampton attacks in the final third. Nathaniel Clyne went close with a long range effort as time wore on, and Ryan Bertrand's deflected effort also went close.

Sadio Mane went in with a horror tackle on van Persie late on and was lucky to stay on the pitch. United though did enough to see the game out and move in to third place in the Premier League table, taking their fifth straight win and leaping past Southampton in the process.

SOUTHAMPTON (4-2-3-1): Forster; Clyne, Fonte, Yoshida, Bertrand; S. Davis, Wanyama; Tadic (Hesketh 70), Long (Mayuka 79), Mane; Pelle.

MANCHESTER UNITED (3-4-1-2): De Gea; McNair (Herrera 39), Smalling (Evans 19), Rojo; Valencia, Fellaini, Carrick, Young; Mata (Fletcher 88) Rooney, Van Persie.