United beat QPR 2-0, but concerns of a Van Persie injury linger A thunderbolt from Rafael da Silva set Manchester United on the way to a 2-0 win at bottom club Queens Park Rangers that sent Alex Ferguson's side 15 points clear in the Premier League.
The Brazilian right-back struck in the 23rd minute, arrowing a crisp, first-time drive right into the top-left corner from outside the box after Julio Cesar had pushed away a shot from Robin van Persie.
The goal came at a cost for United, however, with top scorer van Persie tumbling into the photographers' pit behind Cesar's goal and sustaining a hip injury that forced him off four minutes before half-time.
The evergreen Ryan Giggs sealed victory in the 80th minute, ghosting onto Nani's through ball and whipping a low shot past the exposed Cesar.
Victory gives United a massive lead at the top of the league, ahead of nearest rivals Manchester City's home game with third-place Chelsea on Sunday.
United manager Ferguson sought to play down concerns about van Persie's early exit.
"It's a hip injury, so it might be tender and sore for a few days, but hopefully he'll be all right, particularly for the Real Madrid game (in the Champions League)," he said.
Ferguson also saluted Giggs for helping United to close the game out.
"You have to get that second goal and Ryan Giggs has a great record of scoring here," said the Scot. "He's delivered again - he's an amazing man."
Meanwhile, Arsenal put their recent woes behind them as Santi Cazorla completed a brace with an 85th-minute goal that condemned relegation-threatened Aston Villa to a 2-1 defeat at the Emirates Stadium.
Knocked out of the FA Cup by second-tier Blackburn Rovers and soundly beaten by Bayern Munich in the Champions League, Arsenal were desperate for a reaction and took a sixth-minute lead when Cazorla drilled home.
Arsene Wenger's men failed to build on their lead, however, and in the 68th minute, Andreas Weimann equalised with a 25-yard shot that squirmed beneath Arsenal goalkeeper Wojciech Szczesny.
Yet more unpleasant headlines beckoned, but with five minutes to play, January signing Nacho Monreal scampered down the left wing and cut the ball back for his Spanish countryman Cazorla to guide a low shot past Brad Guzan.
The result took Arsenal to within a point of fourth-placed Tottenham Hotspur, who visit West Ham United on Monday.
"We came out of two massive disappointments and the team were a bit nervous but focused at the start," said Arsenal manager Wenger.
"It's been quite rocky in recent days. It was important to get three points today."
Cazorla's winner also sent Villa into the drop zone and allowed Wigan Athletic to haul themselves out of the bottom three after a potentially crucial 3-0 win at relegation rivals Reading.
A quick-fire brace from Ivorian striker Arouna Kone put Wigan 2-0 up shortly before half-time and Maynor Figueroa added a third early in the second period after a slick one-two with Franco Di Santo.
Reading's misery was complete in the 55th minute when striker Pavel Pogrebnyak was sent off for an ugly lunge on Figueroa.
"The challenge is to stay in the Premier League - it's not an easy one," said Wigan manager Roberto Martinez.
"There are 33 points to play for and I do feel it is going to go down to small margins."
Defeat saw Reading slip below Wigan to second-bottom, although Brian McDermott's side are just a point from safety.
Everton lost ground in the race for Champions League football after Norwich City came from behind to win 2-1 at Carrow Road.
Leon Osman headed the visitors in front from Leighton Baines' cross in the 39th minute, but Kei Kamara levelled six minutes from full-time before Grant Holt lashed in a 94th-minute winner.
On-loan Chelsea striker Romelu Lukaku scored in each half -- the first a penalty -- as West Bromwich Albion won 2-1 at home to Sunderland, who replied through Stephane Sessegnon.
Earlier, a marvellous goal from Dimitar Berbatov gave Fulham a 1-0 win at home to Stoke City that lifted Martin Jol's men to 11th place in the table.
Berbatov lashed a vicious volley into the top-right corner from 15 yards in first-half injury time, while Stoke's Jon Walters saw a penalty saved by Mark Schwarzer after 10 minutes of the second half.

Source: AFP