Manchester United suffered a dispiriting 3-1 defeat at neighbours Manchester City in their 145th derby on Saturday to complete a painful week.
First-half goals by Trevor Sinclair and Darius Vassell and injury-time strike from Robbie Fowler were fair reward for a City side who had taken only one point from their previous four games.
United briefly made it 2-1 with a 76th-minute Ruud van Nistelrooy goal but, down to 10 men after a 66th-minute red card for Cristiano Ronaldo, they were generally toothless in attack.
United's third league defeat of the season leaves them on 45 points, 13 behind champions Chelsea, who visit bottom club Sunderland on Sunday.
Third placed Liverpool (41) host fourth placed Tottenham Hotspur (40) later on Saturday.
Saturday's result completes a miserable week for United, who were held to a goalless FA Cup draw by minor league Burton Albion and managed only a 1-1 draw at Blackburn Rovers in the first leg of their League Cup semi-final.
It was all smiles on the blue side of the city, however. "My team picked up one point out of 12 over Christmas and were a bit low on confidence maybe but we deserved it," City manager Stuart Pearce told Sky Sports.
"We looked like the team who were up for a derby match and took our chances when they came."
CAUGHT FIRE
After a quiet opening half-hour the game caught fire with two City goals in eight minutes.
The first came when Stephen Ireland retrieved a headed Gary Neville clearance and poked the ball back into the box where Sinclair swiveled to drive it first time past Edwin van der Sar.
United looked close to an equaliser three minutes later when Ronaldo set Wayne Rooney clear but City keeper David James raced out quickly to block his England colleague's shot.
City stretched the lead with a route one goal. United failed to deal with a James clearance and when Sinclair's flick on eventually got through to the feet of Vassell the striker kept his cool to sidefoot into the corner.
City continued to comfortably deal with their neighbours' best efforts in the second half and things went their way further in the 66th minute.
Ronaldo, frustrated after being felled by a heavy challenge, launched a studs-up lunge at former United favourite Andy Cole and though he failed to make contact the referee deemed it worthy of a straight red card.
United responded well and cut the deficit in the 76th minute when Ryan Giggs picked out Van Nistelrooy and the Dutchman showed excellent control to chest the ball down, take a touch and swivel to shoot low past James.
They were unable to create much more, however, and were caught on the break in injury time when Vassell set up Fowler crash home the third.