A moment of red card confusion helped Wayne Rooney return Manchester United to winning ways with a brace in a 2-0 Premier League victory over Sunderland on Saturday.

Beaten 2-1 at Swansea City last weekend, Louis van Gaal's United were frustrated by Sunderland until the 64th minute at Old Trafford, when Radamel Falcao won a penalty after being brought down in the visitors' box.

John O'Shea appeared to be the culprit, but referee Roger East elected to send off Wes Brown -- like O'Shea, a former United player -- despite protests from Sunderland's players that he had got the wrong man.

Rooney planted the penalty into the bottom-left corner and then added a second goal to take United up to third place in the table, two points above Arsenal, who host Everton on Sunday.

Asked about the red card mix-up, United manager Louis van Gaal told a television reporter: "That's a mistake. You make mistakes as well, and so do I. It can happen."

He added: "We are on our way and we have been in the top four for more than 10 or 12 weeks. I think we are a stable team in the top four. I hope at the end of the season, we are still there."

Professional Game Match Officials Limited, the body that manages Premier League referees, later released a statement explaining that East felt that Brown had also fouled Falcao and was more deserving of a red card.

Van Gaal made five changes to his starting XI, with Chris Smalling, Jonny Evans, Antonio Valencia, Ashley Young and Falcao brought in as the Dutchman switched to a 4-2-3-1 formation with Rooney at number 10.

Sunderland had enjoyed their two previous visits to Old Trafford, beating United in a League Cup penalty shootout and then winning 1-0 in the league last May, and they started brightly.

United goalkeeper David de Gea had to turn a low shot from Connor Wickham around the post, while Jermain Defoe fired over the bar.

United began to make inroads at the other end, with Young shooting over and then seeing a shot deflected onto the bar by O'Shea, before Sebastian Larsson cleared off the line from Marcos Rojo.

But the home side's play lacked penetration and Van Gaal elected to withdraw the disappointing Angel di Maria at half-time, with Adnan Januzaj coming on.

Southampton slump continues

Then came the penalty incident, with Falcao brilliantly bringing down a right-wing cross and darting away from O'Shea and Brown. O'Shea hauled the Colombian back, but it was an incredulous Brown who was shown the red card.

Rooney's goal saw him end an eight-game scoring drought in the league and he claimed a second in the 84th minute -- his 10th goal of the campaign -- by heading in after Januzaj's shot was parried by Costel Pantilimon.

Southampton lost further ground in the battle for Champions League qualification after sinking to a second successive defeat at West Bromwich Albion.

Saido Berahino scored the only goal in the first minute, slamming home left-footed when Chris Brunt's free-kick was partially cleared by Maya Yoshida, but was later forced off by injury.

"The total performance of the team in quality is a little bit low from the beginning of the season, but we have to go and believe in the next win," said Southampton manager Ronald Koeman.

Southampton trail fourth-place Arsenal by two points and could be overtaken by Liverpool -- who won 2-0 at Southampton last weekend -- if Brendan Rodgers's side win at home to second-place Manchester City on Sunday.

Leaders Chelsea are not in league action this weekend as they play Tottenham Hotspur in Sunday's League Cup final.