The Romanian was handed a shock start as Joe Hart was rested and might have wished someone else was in goal as United scored 3 times. Unfortunate that Rooney scored on the rebound after a superb penalty save but seemed to be caught flat-footed by Welbeck's volley.
The City captain's dismissal in the 12th minute was the decisive moment of the game. Although the Belgian won the ball his reckless, lunging, two-footed challenge on Nani was completely unnecessary.
Appeared to lose his bearings next to an unfamiliar partner in the first-half following the red card but far more assured after the break. Good reading of the game and organised the backline in Kompany's absence.
For a player whose priority is to defend, the Serbian's bad outweighs his good. Poor positionally against Valencia and conceded the penalty for a poor, mistimed challenge on Welbeck whilst he should have given away another for a clumsy tackle on Valencia in the second-half. Superb free-kick curled over the wall from 25 yards gave City hope three minutes after the re-start.
Looked uncomfortable in central defence after Kompany's red card but his marauding runs from right-back were a key feature of City's near recovery. Won the free-kick for the first goal and went up front for the final minutes.
As ever, a hard-working performance both in central midfield and at right-back. Never gave up despite finding the game tough with City a man down and produced an excellent cross for Aguero's goal.
The Spaniard started very brightly in the first 10 minutes, drifting around the pitch and looking to link up with Aguero. Virtually disappeared from the game after Kompany's red card and was replaced by Savic at half-time as City reverted to a five-man defence.
The Frenchman was neat and tidy on the ball and it was telling that Mancini chose to keep him on the pitch for the second-half rather than Silva. Looked to set City on the counter-attack before being replaced by Hargreaves eight minutes from time.
Roberto Mancini has never fancied the winger as the sort of player he needs when his players have to roll their sleeves up. Started well - like the rest of the City team - but had almost no involvement once the game went in United's favour.
N. de Jong
The Dutchman is no longer an automatic starter but his style suited this derby encounter. Hassled and harried the United midfield as much as he possibly could and ran himself into the ground.
Found it tough as City's lone striker and had little support once the hosts were reduced to 10 men. Scored with a typically predatory finish on the rebound after his initial shot was saved.
The Dane was once again selected ahead of David de Gea. Made a sharp stop to deny Aguero in the first half but will be disappointed with his poor attempt as the Argentine scored City's second goal. Looked very shaky as United came under pressure in the dying stages.
Calm and composed display, especially in the first-half, as he anticipated City attacks with apparent ease. Lack of pace exposed after the break when Aguero ran the channels.
Looked far more comfortable at right-back than central defence. Solid defensively and always looked to join Valencia in attack. Very lucky to get away with clear handball from Kolarov cross eight minutes from time.
Gave away the free-kick ahead of City's first goal and nowhere to be seen as Milner crossed for the hosts' second. Always dangerous going forward and was involved in Welbeck's goal after a strong overlapping run.
Commanding display for much of the game at centre back as he dealt with Aguero and won huge headers in the final minutes. Made one mistake, however, as he was slow to react to the rebound for City's second goal.
Started United attacks with precise passing and good positioning. Seemed to tire in the second-half but was valuable as the visitors looked to run the clock down.
The Welshman was constantly abused by the City fans, so the victory would have felt all the more sweeter for him. His experience was needed as United panicked in the last 20 minutes or so - although he looked uncomfortable on the wing.
The Portuguese winger is known for his on-field theatrics but shouldn't be blamed for Kompany's red card as he didn't react to the Belgian's challenge. Offered width but lacked penetration before being replaced by Scholes in the 59th minute.
The Ecuadorian showed the quality of his delivery as he crossed for Rooney to head United ahead in the 10th minute. Hugged the touchline, constantly beat Kolarov and delivered the ball into the box. Should have won a penalty in the second-half when he was hacked down by the Serbian.
It had to be him after the recent headlines about fall-outs with Ferguson and a potential sale. Superb 10th minute header gave United the lead and he made it three in the five minutes before the break, nodding home after seeing his initial penalty saved.
The young striker was as bright as a button, particularly in the first-half as he looked to link play around the edge of the City box. Brilliant volley on the turn to put United two up and won the penalty after inviting a rash challenge from Kolarov.
- J. Hart
Replaced Johnson at half-time and gave a very solid defensive display as City played their way back into the game in the second half.
- G. Clichy
Replaced Silva at half time to slot into a five-man defence. Strong in the air and committed as he continued on despite a nasty wound to his head.
- Denis Suárez
The former United man came on for Nasri eight minutes from time but had little involvement.
- A. Razak
- De Gea
- J. Evans
- Ji-Sung Park
The United legend, on his shock comeback from retirement, replaced Nani in the 59th minute. Looked rather rusty at first, especially as he conceded possession in the build-up to City's second goal, which was scored by Aguero. Seemed to recover well and his intelligent use of the ball helped United keep possession and relieve the pressure.
Replaced Welbeck 15 minutes from time, adding fresh legs as United looked to see the game out.
- J. Hernández