Man U lose control, but win
To make matters worse for City, they had enjoyed a commanding opening spell before the visitors scored with their first foray into the home half, a move started by a Ryan Giggs pass to Rooney.
The forward fed Antonio Valencia wide on the right before moving into the area and meeting the winger’s cross with a spectacular header that went in via the underside of the bar.
And within two minutes City were left with even more of a mountain to climb after referee Chris Foy felt that Kompany’s two-footed, sliding challenge on Nani warranted a red card.
It appeared a harsh decision, given that the City defender won the ball without making contact with his opponent and Nani did not even appeal for a foul.
On the half hour, United seemed to have taken a stranglehold on proceedings when Welbeck doubled the lead.
Nani played an intelligent ball to the overlapping Patrice Evra, whose low cross eluded Welbeck only for Samir Nasri to inadvertently help it back into the path of the United forward, who volleyed home spectacularly.
United could sniff blood, and a large measure of revenge for their humiliating 6-1 home league loss to City earlier this season.
After 38 minutes and another incisive Giggs pass, they stretched their lead further when Welbeck was tripped by Kolarov.
Rooney took a poor penalty, which was saved by Costel Pantilimon, but responded quickly to the rebound and headed it into an open net.
City manager Roberto Mancini brought on defenders Pablo Zabaleta and Stefan Savic at half-time as part of a tactical reshuffle, and the move paid instant dividends when Evra brought down Micah Richards after 48 minutes.
Kolarov made it 3-1 with a spectacular 22-yard free kick that beat the United wall and the dive of Lindegaard.
Nani headed wide and Rooney’s latest long shot whistled past the post before United manager Sir Alex Ferguson drew huge cheers from the visiting supporters by replacing Nani with Scholes just before the hour. United felt they should have had a penalty when Kolarov tripped Valencia in the area, but referee Foy was unmoved and soon afterwards City made it 3-2.
Ironically, Scholes was badly at fault for the goal, gifting the ball to James Milner with an indifferent pass deep in United territory.
Milner’s right-wing cross found Aguero, whose initial shot was only parried by Lindegaard, but the City forward scored from the rebound.
United tried to take the sting out of City’s recovery, but lived dangerously when Phil Jones appeared to handle a Kolarov cross but escaped with only conceding a corner.