FA Cup - United beat 10-man City in FA Cup classic
The scoreline may not have matched the 6-1 result City recorded at Old Trafford back in October, but two goals from Wayne Rooney and another from Danny Welbeck came in a first half in which Vincent Kompany was sent off after just 12 minutes and were enough to end City's cup defence at the first time of asking.
United also made amends for their defeat at the semi-final stage of the same competition last season, but the victory did not quite strike the psychological blow on their main title rivals they might have hoped as 10-man City pulled two goals back in the second half through Aleksandar Kolarov and Sergio Aguero.
United made the short trip across town on the back of two straight defeats, but their fans were given an unlikely boost just an hour before kick-off when the club announced that their legendary midfielder Paul Scholes has re-signed with the club until the end of the season, and that the 37-year-old would be on the bench for the 161st Manchester derby.
City were missing Edin Dzeko and Mario Balotelli through injury, while the Toure brothers Yaya and Kolo have departed for the African Cup of Nations. Despite that, they began by far the better side, pinning their visitors back for much of the opening 10 minutes in the kind of free-passing slick style that has come to define them this season.
Then, completely against the run of play, United were ahead with their first attack of the match after 10 minutes.
Rooney played the ball out wide to Antonio Valencia, continued his run into the box and met the Ecuadorian's cross with a bullet header that hit the top corner. Romanian goalkeeper Costel Pantilimon was in the City goal as Roberto Mancini decided to rest Joe Hart, but there was nothing even the England number one could have done to stop City conceding their first goal in six FA Cup matches.
Things went from bad to worse for City when their club captain Kompany was sent off just two minutes later. The Belgian went into a tackle on Nani that referee Chris Foy judged to have been two-footed and reckless and showed no hesitation in showing a red card for the seventh time this season.
City actually created a few decent chances after going down to 10 men – Aguero forced a fine save from Anders Lindegaard and hit the side netting while David Silva's shot was blocked after a dazzling run – but it was United who were now dominating and they were soon two goals up.
Just after the half-hour mark Patrice Evra's ball from the byline was deflected into the air off Lescott and Aguero, but Welbeck reacted brilliantly to swivel and fire a right-footed volley right inside the far post. It was his seventh goal of the season and only his second since October 1.
Soon afterwards it seemed the match was over as a contest when Kolarov brought down Welbeck in the area. Rooney's spot-kick was saved by Pantilimon but he reacted quickest to head home his second and United's third.
That goal meant the run-up to half-time was tortuous for City supporters, with United's players toying with their team and the visiting fans imitating their famous 'Poznan' celebration in their own ground.
Just three minutes after the restart, City fans were given reason to dream when Kolarov scored a free-kick. The Serbian full-back usually blasts his set pieces, but on this occasion he went for placement and his well-measured strike dipped over the wall and out of Lindegaard's reach.
That goal early in the second half may have sparked memories of a 10-man City team battling back from 3-0 down to beat Tottenham 4-3 in February 2004, but United remained in control to such an extent that Alex Ferguson brought on Scholes with more than half an hour remaining.
The veteran midfielder had a mixed second debut in which he was often in the thick of things for United as though he never left, but then also lost possession on a few occasions.
One such occasion saw a sloppy 64th-minute pass intercepted by Milner, whose low cross found Aguero. The Argentina striker's initial effort was saved by Lindegaard but he side-footed the rebound to reduce the deficit to one goal.
Both sides had strong claims for penalties turned down by Foy for perceived offences by Kolarov and Jones, but it was City who often looked more likely to score the sixth goal of the match.
In the final minute of stoppage time they won a corner, giving cause for six-foot-eight keeper Pantilimon to trundle up for the set piece. The big keeper got his head to the ball and glanced it wide, but it was a fitting end to a thrilling cup tie that few in Manchester or anywhere else will forget in a hurry.