Wayne Rooney steered Manchester United to a 2-0 victory over Sheffield United that sent them six points clear at the top of the Premier League on Tuesday.
Rooney's side was looking to keep the pressure on second-placed Chelsea, who visit West Ham United on Wednesday, and took a fourth-minute lead through midfielder Michael Carrick.
England striker Rooney made sure of the points five minutes into the second half at Old Trafford, lashing the ball home after a fine move.
Arsenal climbed to third with a 3-1 home victory over Manchester City in the night's other game.
Manchester United are on 81 points from 33 games while champions Chelsea have 75 from 32. Arsenal have 62 from 34 matches, one point ahead of Liverpool who host Middlesbrough on Wednesday.
It was a lacklustre performance from Manchester United, who made an ideal start when Carrick latched on to an angled pass from winger Cristiano Ronaldo and sent the ball over keeper Paddy Kenny.
Rooney made it 2-0 after controlling a ball over the top from winger Ryan Giggs and adding a superb finish for his 20th goal of the season.
Manchester United, already hit hard by injuries in defence, lost left back Patrice Evra to a rash 21st-minute challenge from Colin Kazim-Richards.
It left the hosts with two midfielders at full-back, Kieran Richardson on the left and Darren Fletcher on the right.
Manager Alex Ferguson said Evra would have a scan on Wednesday.
"It was a pleasing result and our performance was...maybe the word is economical. We didn't kill ourselves, which was important," Ferguson told Sky Sports.
With five league matches to go, he said: "I look on most games now as cup finals, they're all so important. The form of the team is good...and they've got the right temperament."
ARSENAL GRIND
Arsenal ground out victory in the closing stages at the Emirates Stadium.
Czech midfielder Tomas Rosicky gave them a 12th-minute lead but American midfielder DaMarcus Beasley levelled for City against the run of play before the break.
Spain midfielder Cesc Fabregas, who got Arsenal's winner on Saturday against Bolton Wanderers, restored the advantage with a 73rd-minute volley before Brazilian Julio Baptista netted after good work by Belarus midfielder Alexander Hleb.
Arsenal manager Arsene Wenger felt Fabregas's strike was the turning point.
"That changed it because straight away City changed their shape and opened up more," he said. "Then we had many chances to score the third."
