Alex Ferguson's side blew Chelsea away thanks to three goals in the first half from Chris Smalling, Nani and Wayne Rooney.
Fernando Torres pulled one back for the visitors in the second half, with Rooney also missing from the penalty spot, but United's fifth win in five matches moved them to the top of the Premier league table ensured them 2 points advantage over second placed Manchester City's which drew at Fulham, Chelsea is at third place 5 points behind Manchester United.
Smalling opened the scoring with his first Premier League goal in the eighth minute before Nani doubled the lead from long range.
Rooney added a third just before half time, his ninth in five Premier League outings this season.
Rooney added a third just before half time, his ninth in five Premier League outings this season.
It was Chelsea's first loss under new boss Andre Villas-Boas, who tasted defeat in a league game for the first time since April 2010 when Benfica beat his Academica de Coimbra team.