For only the third time in its last 38 1 on Sunday.
Mario Balotelli scored the lone goal in a cautious first half with a nice first-time strike from the edge of the penalty area, but the match turned just one minute into the second half when United's Jonny Evans was sent off for pulling back Balotelli as he attempted to race in on goal.
The City striker tallied his second goal of the game on the hour mark by finishing off a cross from James Milner, while Sergio Aguero netted his ninth goal in league play eight minutes later after a right-wing feed from Micah Richards.
United managed to pull a goal back nine minutes from time through Darren Fletcher after a one-two with Javier Hernandez, but the hosts switched off in stoppage time and were punished with three more City goals.
Edin Dzeko scored twice and David Silva added a goal of his own to further inflate the final score, giving City an emphatic three points and keeping Roberto Mancini's men alone at the top of the league with 25 of a possible 27 points.
United has hit a bit of a rough patch with only five points earned from its last four games.
QPR 1, Chelsea 0
London, England - A 10th-minute penalty kick from Heidar Helguson was the difference as QPR claimed a 1-0 win over Chelsea at Loftus Road on Sunday in a match that saw both Jose Bosingwa and Didier Drogba sent off for the visitors.
David Luiz was guilty of a foul on Helguson inside the penalty area in the 10th minute, and the QPR man picked himself up and floated his spot kick over a diving Petr Cech in the Chelsea net.
But things got worse for the Blues shortly after the half-hour mark as Bosingwa was sent off for pulling down Shaun Wright-Phillips to deny a scoring opportunity.
Drogba also saw red before halftime for a two-footed challenge near midfield that summed up a frustrating afternoon for Chelsea, which remains in third place in the league.
Arsenal 3, Stoke City 1
London, England - Arsenal has began to turn things around after a poor start to the campaign as the Gunners collected their fourth win in six games on Sunday, beating Stoke City 3-1 at the Emirates Stadium.
Gervinho's goal midway through the first half was canceled out six minutes later by Peter Crouch for Stoke. But Robin van Persie carried Arsenal to three points with two goals in the final 18 minutes to give the Dutchman seven on the campaign.
Arsenal moves into the top half of the league with the win, while the Potters have claimed only one win from their last five matches.
Everton 3, Fulham 1
London, England - Everton snapped a string of three successive defeats on Sunday as Louis Saha and Jack Rodwell scored late goals in a 3-1 win for the Toffees over Fulham at Craven Cottage.
Royston Drenthe got Everton off the mark after three minutes and his goal held up until the 66th minute when Bryan Ruiz equalized for the home side.
But Saha picked a good time to notch his first goal of the season in the 89th minute when he latched onto a header from Drenthe and beat goalkeeper Mark Schwarzer.
Rodwell then secured the win with a goal three minutes into added time, leaving Fulham with one win from nine games and floundering near the bottom of the league.
Tottenham 2, Blackburn 1
Blackburn, England - Blackburn slipped to the bottom of the Premiership table on Sunday after a pair of goals from Rafael Van der Vaart handed Tottenham a 2-1 victory over Rovers at Ewood Park.
Van der Vaart scored his first goal after 15 minutes, while Blackburn equalized before halftime through Mauro Formica.
However, the Dutchman netted his second goal of the game eight minutes after the break to give Spurs five wins from their last six games.
Blackburn has earned one point from its last four matches.