English champions Manchester United suffered a historic 6-1 defeat at home to leaders Manchester City in an extraordinary derby on Sunday. Mario Balotelli fired City in front with a brace as Sergio Aguero added a third before Darren Fletcher pulled one back for United. But Edin Dzeko came off the bench to score twice and set up David Silva with another goal in the space of two minutes. City extend their gap with United to five points after nine weeks. United 1-6 City