Carlos Tevez scored twice against his old club as Manchester City came from behind to take a narrow advantage into next week's Carling Cup semi-final second leg.
Manchester United led through Ryan Giggs' 17th-minute tap-in but City drew level after Rafael hauled back Craig Bellamy inside the box.
Tevez gleefully rammed home the penalty, then turned home Vincent Kompany's cross from close range after the interval, each celebration twisting the knife on Alex Ferguson and Gary Neville, who only this week backed his manager's decision to let the South American leave Old Trafford.
