Sergio Aguero's goal ensured Louis van Gaal's first Manchester derby ended in defeat as Manchester City beat 10-man Manchester United 1-0 at Eastlands on Sunday.
United manager Van Gaal's side had to play more than half the match a man down as defender Chris Smalling was sent off in the 39th minute after collecting two needless yellow cards, having charged down goalkeeper Joe Hart's clearance kick before a reckless foul on James Milner.
City had several penalty appeals rejected by referee Michael Oliver before Aguero fired City into a 63rd-minute lead after finishing from close range to crown a superb one-touch move involving Yaya Toure and Gael Clichy.
The Argentinian striker's 10th league goal of the season left him top of the Premier League scoring charts after he had been tied on nine with Chelsea's Diego Costa heading into this weekend's round of matches.
Hart then saved well from Angel di Maria to deny United an equaliser 14 minutes from time before Marouane Fellaini wastefully headed wide when well-placed to make it 1-1.
Victory in front of their own fans saw Premier League champions City move to within six points of leaders Chelsea as they ended a run of three games without a win in all competitions.
But they remained third in the table, two points adrift of second-placed Southampton.
- City end winless streak -
Recently City have been held to a disappointing 2-2 draw away to CSKA Moscow in the Champions League and been beaten beaten in the league by West Ham.
They also saw their defence of the English League Cup end with a 2-0 loss at home to Newcastle in midweek but Sunday's result was just the tonic they needed ahead of their return Champions League group clash with CSKA.
"It is a boost for us and we will do our job again in the Champions League on Wednesday," said City captain Vincent Kompany.
United's defeat, and Tottenham Hotspur's 2-1 win over Aston Villa later Sunday, meant they dropped to 10th place and remained 13 points off the summit, with Dutch boss Van Gaal still to record his first away league win as manager.
"I said to the boys that the willpower, the labour was unbelievable," said Van Gaal, who explained he had no complaints regarding Smalling's "logical" dismissal.
"When you can give that, you can be very proud but we have zero points and in sport it is always the goals that count," he added, with United's haul of 13 points from 10 games representing their worst start to an English top-flight season since 1986/87, when Ron Atkinson was sacked as manager and replaced by legendary boss Alex Ferguson.
In Birmingham, Tottenham came from behind to beat 10-man Villa 2-1, with substitute Harry Kane's deflected free-kick in the 90th minute sealing victory for the visitors.
Andreas Weimann's 16th-minute goal -- Villa's first in more than five matches -- put the hosts ahead but they had to play the final 25 minutes a man down after Christian Benteke was shown a red card for a slap on the face of Tottenham's Ryan Mason.
Spurs eventually made their advantage pay by scoring two goals inside the final six minutes at Villa Park.
Nacer Chadli struck from an Erik Lamela corner before the 21-year-old Kane, a product of north London club Spurs' youth system, grabbed the winner.
Victory saw Spurs climb to eighth place, six points above the relegation zone but Villa's sixth loss in a row left them just two points above the bottom three.
"Without a doubt it was one of the greatest moments for me in a Spurs shirt in my career so far," said Kane.
Villa manager Paul Lambert was frustrated by Benteke's dismissal, saying: "You cannot condone what he did but it is not like he threw a Mike Tyson punch. My daughter can punch harder than that."
Source: AFP