A controversial goal from substitute Javier Hernandez helped Manchester United snatch a 3-2 win at nine-men Chelsea.
United raced into a 2-0 lead in the first half thanks to David Luiz’s fourth minute own goal and a neat Robin van Persie strike eight minutes later.
But a superb free-kick from Juan Mata just before the interval gave the hosts some hope.
And when Ramires headed home eight minutes after the restart to complete the Chelsea comeback, it looked like United were going to leave the capital with no more than a point at best.
Referee Mark Clattenburg then sent off Branislav Ivanovic for a foul on Ashley Young before Fernando Torres picked up a second booking for diving to reduce Chelsea to nine men.
United boss Sir Alex Ferguson smelt blood and introduced Hernandez and it was his strike, when coming back from an offside position, that proved to be the winner.
The win lifts the Reds to within a point of Chelsea at the top of the Barclays Premier League table.