Roberto Mancini's men began slowly but soon kicked into gear as Mario Balotelli scored in each half and Sergio Aguero put the finishing touches on things with just over 20 minutes left before Edin Dzeko (2 goals) and David Silva helped themselves to late goals to complete the celebrations and inflict United's heaviest ever home defeat.
United defender Jonny Evans was sent off for pulling Balotelli back as the last defender denying a goalscoring opportunity early in the second half and it was after that incident that City really took control before Darren Fletcher gave the home side a touch of hope with a superb goal with ten minutes left but Dzeko and Silva finished it off with three more goals in the last few minutes to make it a huge scoreline for City.
The opener came in the 22nd minute with a good build-up from the visitors which saw Silva play it out to the left for James Milner. He played it back to the top of the area for Balotelli who stroked it home inside the far post with a cool, composed finish which gave David De Gea no chance in United goal.
The second came just before the hour when Milner played in Silva, who spun Anderson in the area and slid it back into the path for the England midfielder who then found Balotelli at the back post for a simple finish.
United were finished off with just over 20 minutes remaining when Micah Richards was found on the right side of the area before supplying Aguero with a sliding finish with his 10th goal in his past nine City outings.
With 10 minutes remaining, Darren Fletcher gave United some slight hope when he scored with a remarkable curling effort from outside the area for his first goal in the league for a year but it was to no avail as substitute Dzeko scored his seventh goal of the campaign in simple fashion when Joleon Lescott tapped it back for him on the goal-line before Silva slotted between the legs of De Gea.
Silva supplied an absolutely brilliant cushioned volley into the path of Dzeko in injury time and the Bosnian took a touch before finishing with his left as the Etihad Stadium outfit made it a huge party for all City fans and made a massive statement from a Premiership viewpoint.
City are now in a commanding position at the summit of the Premier League with 33 goals from nine outings and just seven against as Sir Alex Ferguson goes back to the drawing board as they are now in danger of giving up second spot depending on the Chelsea result later today.
TRIBAL ASKS: Does this result make Man City the title favourites?
Yellow cards:MANU - Anderson 62', Patrice Evra 67', Chris Smalling 79', Danny Welbeck 83' MANC - Mario Balotelli 23', Vincent Kompany 41', Edin Dzeko 75', Micah Richards 86' Red card:MANU - Jonny Evans 47'