United's lead in the Barclays Premier League was reduced to one point on Wednesday night - but only just, as rivals Manchester City survived a scare.
Roberto Mancini's men went 1-0 down on the hour mark at the Etihad Stadium when Chelsea defender Gary Cahill scored a scrappy goal, and the home side needed a 78th-minute penalty converted by Sergio Aguero - after handball by Michael Essien - to equalise.
City were then poised to drop two home points, but snatched all three when former United striker Carlos Tevez - making his controversial return to action for the Blues - set up ex-Arsenal midfielder Samir Nasri for a priceless winner in the 85th minute.
The 2-1 success was City's 20th consecutive home win in the league, setting a new record for the Premier League. More importantly, it gives them the chance to go back into pole position above United on Saturday evening - albeit having played one game more - by either drawing or winning away at Stoke City's Britannia Stadium.