If Manchester City do pull off the impossible and overturn United's lead atop the Premier League, Joe Hart's penalty save from England colleague Frank Lampard will undoubtedly be the turning point where everything changed.
The reigning champions bounced back from their loss to Southampton in their last match to beat third placed Chelsea 2-0 with goals from Yaya Toure and Carlos Tevez.
The game was also notable for a start for City's Jack Rodwell, making his comeback from injury at the heart of the club's midfield. His last appearance was as a substitute in the 0-0 draw at QPR, and before that he hadn't been seen since October.
A £15 million signing from Everton, he arrived with an 'injury-prone' reputation so it came as no big surprise, what the watching world is now interested in is whether he can stay fit and how he performs when he gets on.
His third league start of the season, Rodwell played 54 minutes, taken off for Carlos Tevez as part of a tactical re-adjustment, which paid dividends as just two minutes later Yaya Toure broke the deadlock.
Despite playing just under an hour, Rodwell had as many shots on goal as any other City player, equaling Yaya Toure with four, each with two on target.
Rodwell also won more aerial duels (four) than any other City player on the pitch, and while his passing accuracy of 79 per cent does not appear high, it was only marginally less than Toure (80 per cent) and more than fellow midfielder James Milner (76 per cent).
But those are just statistics; how did Manchester City fans react to his display - satisfied with the promise? Or underwhelmed? Here is a selection of comments from Twitter...
@etihad_stadium: Thought Rodwell would've been a strong contender for man of the match today. Unlucky to be taken off
@ste_sully: Rodwell played well today. First time I've seen him dominant & not timid. Mancini seems to have been working with him
@matthewjoyce11: Funny how everyone was slating Kolo and Rodwell before the game and yet they were the best players on the pitch
@c_clayton01: Javi Garcia and Rodwell had their best games in a city shirt today
@invisiblemanmc: Rodwell was outstanding today. Signs of De Jong on his performance today. Got stuck in.
@mattfunge91: I said back in October that Rodwell was a brilliant signing for us. Started season very well before injuries disrupted. Great today.
What did you think of Rodwell, what can he offer City over the coming months, and importantly - can he stay fit?
image: © geetarchurchy