Dimitar Berbatov struck both goals for United in a 2-0 victory over Sunderland as Sir Alex Ferguson's team emerged from a two-week layoff caused by the icy winter weather that has played havoc with the sporting calendar.
United lead the table with 37 points from 17 games, with Manchester City up into second spot with 35 from 19 after Argentina striker Carlos Tevez netted twice in their 3-1 victory at Newcastle United.
Third-placed Arsenal can move back ahead of City when they host champions Chelsea, in fourth, on Monday.
Tottenham Hotspur stayed in touch with the leading quartet after Dutch playmaker Rafael van der Vaart scored both goals in a 2-1 victory at Aston Villa.
Spurs, who played for more than an hour with 10 men after Jermain Defoe was sent off, have 30 points from 18 games.
Bolton Wanderers are sixth on 29 points after beating West Bromwich Albion 2-0. Stoke City overcame Blackburn Rovers 2-0 while Carlton Cole struck twice to help West Ham United off the bottom with a 3-1 victory at Fulham.
Wolverhampton Wanderers are now propping up the table after losing 2-1 at home to Wigan Athletic.
Bulgarian Berbatov returned to United's starting line-up after being left out against Arsenal two weeks ago and took just five minutes to make his mark, heading in a cross from Wayne Rooney at the end of a flowing move.
United should have sealed the points before halftime according to manager Ferguson, who described some of their play as "fantastic", but had to wait until the 57th minute for Berbatov to double the advantage with a deflected shot.
Often maligned as not hard-working enough, Berbatov's goals have kept United on track this season as Rooney has struggled to find his shooting boots.
With 13 league goals, Berbatov leads the top flight's scoring charts.
"He knows there are times we like to play with one up front and he understands we have to sometimes change things around. But his form has been terrific," Ferguson told Sky Sports News.
"If we get two players to score 25 goals between them then we have a great chance (of winning the title).
"The first half was the highlight. Some of the football was fantastic and we could have scored four or five. We were pretty economical with our performance in the second half."
Just two weeks after handing in a transfer request that he later retracted, former United striker Tevez showed exactly why he is vital to City's ambitions.
Tevez doubled City's lead after Gareth Barry opened the scoring and later killed off a Newcastle revival after the break to take his league tally to 12 goals this season.
"I am happy Carlos scored two goals and he is a great player but I'm happy because all the players did well today especially (midfielder) James Milner,"
