Chelsea march on with walloping of Wolves
United kept pace with the leaders by beating Everton 3-0 at home in the late match to move up to second after Arsenal's 14-match unbeaten run ended with a 1-0 defeat at Sunderland.
Chelsea, who set a club record of 12 straight home wins, have 33 points from 13 matches to United's 28. Arsenal are on 25 with a game in hand.
Carlo Ancelotti's sparkling Chelsea side were dominant from the start at Stamford Bridge, strolling into a 3-0 lead after 22 minutes with Florent Malouda opening the scoring with a left-foot shot in the fifth.
Michael Essien made it 2-0 with a 12th minute header and grabbed another 10 minutes later. Joe Cole made it 4-0 in the 56th, unleashing a low, right-foot shot off a pass from Salomon Kalou for his first league goal in more than a year.
"It was an easy game because we played very well," Ancelotti, who gave French teenager Gael Kakuta his Premier League debut, told Sky Sports. "When Chelsea play at their best, it's difficult to play against Chelsea."
Wolves stayed second from bottom with manager Mick McCarthy saying: "We are in a relegation dogfight from now on."
United went ahead in the 34th minute at Old Trafford when Darren Fletcher smacked a swerving half-volley into the top left corner and doubled their tally in the 67th through Michael Carrick.
Antonio Valencia made it 3-0 with a deflected shot in the 76th after the ball was laid on by Paul Scholes.
"The second goal put us in the comfort zone and from there on I didn't think we could possibly lose it," United manager Alex Ferguson told ESPN television.
"If we get to the New Year within a point, or a point ahead, or level, then we have a great chance (to win the title) in the second half of the season."
Injury-hit Liverpool and big-spending Manchester City squandered their chance to move up to fourth place after battling to a 2-2 draw at Anfield in the lunchtime kick-off.
Sunderland had Darren Bent to thank after his 71st minute goal stunned Arsene Wenger's high-scoring Arsenal.
"We stifled them in the middle of the park," said Sunderland manager Steve Bruce. "It's okay to have a game plan but you've still got to go out and do it and they (Sunderland's players) stuck to their task."
Wenger, without injured Dutch striker Robin van Persie, said: "It is a big setback. You do not prepare yourself to drop points in a situation like that. It's frustrating."
Liverpool, in danger of going out of the Champions League next week, were forced into making two unscripted substitutions within the first 18 minutes of a scrappy first half at Anfield.
Defender Daniel Agger suffered concussion and needed five stitches after collapsing with a gashed forehead in the fifth minute following a clash with Kolo Toure in the goalmouth.