From staring a four-point deficit in the face, long-time league leaders City pulled a 2-1 victory out of the fire against Chelsea, the-85th minute winner from Samir Nasri being superbly created by the quick-thinking of back-in-favour Carlos Tevez.
They now trail by just a point and victory, or even a draw at Stoke, would allow City to retake the lead, at least until United host Fulham on Monday.
Below the battle for the title, Arsenal have emerged as favourites to grab the third automatic qualification place for the Champions League after a six-match winning run put them above North London rivals Tottenham Hotspur.
Arsenal, who have 55 points, host Aston Villa while Tottenham (54) face a trip o fifth-placed Chelsea (49) hoping to get back to winning ways after managing just one point from the last 12 up for grabs.
Third-bottom Bolton Wanderers return to action at home to Blackburn Rovers after their midweek match against Aston Villa was postponed following the cardiac arrest suffered by their midfielder Fabrice Muamba last week at Tottenham.
Muamba remains in hospital but is showing signs of making a remarkable recovery.
Tevez has hardly been missed at City this season, such has been the club's form in his absence since he refused to come off the bench in a Champions League match in Munich in September.
However, City's lead at the top has evaporated because of patchy away form and a lack of goals and suddenly Tevez, whose 24 goals helped the club to the FA Cup and third place in the league last season, looks as though he could still play a decisive role in what has been a traumatic season.
Manager Roberto Mancini, who has patched up his differences with Tevez despite saying he would never play for the club again in September, sent the Argentine dynamo on for the final 20 minutes against Chelsea and was rewarded with a livewire cameo performance helped seal three precious points.
"Carlos is two or three weeks away from full fitness but he showed his football brain in the minutes that he was on the pitch," Mancini told the club's website.
"He will be an important player for us. He has been back a month now and is in the dressing room happy like all the players."
City will be without Joleon Lescott at Stoke but fellow central defender Vincent Kompany, who also missed the Chelsea win, could return.
United, who have bagged 25 points from their last nine games to take control, will have Phil Jones available for the trip to Fulham after recovering from flu while Nani is also in the running for a return after missing the league wins over West Bromwich Albion and Wolverhampton Wanderers.
"There are no problems with injuries," manager Sir Alex Ferguson told the club's official website. "It's much better now. There was Jones getting that bout of 'flu but he's back.
"He'll be available [for the Fulham game]. They're all training apart from Nani, who should not be far away and might start training this week."
