A deflected Juan Mata strike gave Chelsea a victory at a lacklustre Manchester United which lifts the Blues up to third in the Premier League.
Earlier, Oscar’s shot for the visitors was palmed on to the post by keeper Anders Lindegaard before United’s Robin van Persie glanced a shot just wide.
The match appeared to be petering out when Mata’s 87th minute shot went in off Phil Jones and the post.
Moments later, United’s Rafael was sent off for kicking David Luiz.
The Brazilian defender was seen smiling on the ground after Rafael’s crude challenge as the game ended in the kind of fiery intensity the match had largely lacked.
With victory edging Chelsea a point ahead of Arsenal in the race for the Champions League places, Rafael Benitez’s men – who have a game in hand over the Gunners – will be more satisfied by the win than the quality of their performance.
The Blues are three points in front of fifth-placed Tottenham, who they play on Wednesday. If Chelsea win that game it should all but guarantee them a top-four place.
After both of their London rivals had won on Saturday, the pressure was on Chelsea to follow suit in their 65th match of the season.
In what was also their 12th game in 37 days, the visitors quickly took the initiative and created the first threat on goal, with the teasing Mata crossing for the stretching Demba Ba to head over.
Another Mata cross fell to Ba at the far post and, although the Chelsea forward did well to take the ball down on his chest, he could only strike an air shot before United cleared their lines.
There was a lack of zip and urgency about the home side and they almost paid the price when Oscar ran unchallenged at goal before having a shot palmed onto the post by Lindergaard.
Chelsea failed to provide the cutting edge to capitalise on the Old Trafford side’s lack of intensity, with Victor Moses sweeping a shot over as the Blues again squandered a promising opening.
United’s disciplined and determined defending was their saving grace before they briefly found some attacking rhythm, with Van Persie twice going close just before the break.
The Dutchman latched onto an incisive pass from Ryan Giggs only to glance a shot just wide before Van Persie headed straight at Blues keeper Petr Cech from a Nemanja Vidic cross.
Chelsea responded by trying to increase the pace of the game after the break, although they struggled to prise a way through the United backline as chances were hard to come by at both ends.
However, there was to be late drama.
Chelsea midfielder Ramires tackled Wayne Rooney on the edge of the Blues box before powering forward and passing to Oscar, who laid the ball off for Mata to send a shot in off Jones and the post.
United were angry the challenge by Ramires was not deemed a foul, while Rafael’s frustration boiled over into a cynical challenge on Luiz as he incurred his side’s first red card of the season.
Manchester United boss Sir Alex Ferguson:
“There is always an expectation that we should do better. We expected a better performance. After the goal we had no time to get back in the game.
“It was difficult for players coming in. Chelsea had everything to play for.
They [some of our players] haven’t played for quite a while. That being said, we should be doing better.
“He [Rafael] retaliates but he [David Luiz] quite clearly elbows him twice then rolls about like a dying swan, and that convinces the referee. He was smiling, it’s bad. What kind of professional is that?”