* Late winner sinks City after comeback
* Ferdinand bloodied by missile thrown by fan (Adds details, quotes)
By Sonia Oxley
MANCHESTER, England, Dec 9 (Reuters) - Robin van Persie's stoppage-time free kick snatched a 3-2 victory for Manchester United in a pulsating derby at champions Manchester City to send them six points clear at the top of the Premier League on Sunday.
Wayne Rooney put the visitors ahead in the 16th minute against the run of play with a softly struck effort into the bottom left corner before doubling his tally just before the half-hour mark.
City pulled one back through Yaya Toure on 60 minutes before levelling in the 86th minute with Pablo Zabaleta's sweetly struck shot but any thoughts of a draw were short-lived when Van Persie launched a free kick into the bottom left corner.
United's celebrations were marred when defender Rio Ferdinand was left bloodied above his left eye after being struck by an object thrown from the crowd.
The result ends City's almost two-year unbeaten home run in the league, stretching back to December 20, 2010, and puts United in the driving seat in the title race with 39 points from 16 matches, while City are on 33.
"Today was special because they hadn't lost at home for two years and both of us are contending at the top of the league," United manager Alex Ferguson told Sky Sports.
"It was a fantastic game and you couldn't take your eyes off it. We should have killed the game off but it's a funny game football, instead of being 3-0 it was 2-1 and it got the fans going."
The "Champ1-0ns" banner taunting the United fans summed up the significance of the match, referring to the 1-0 victory by City over their neighbours at the Etihad Stadium late on last season which turned the title race in their favour.
Having lost out on the championship on goal difference to Roberto Mancini's side, United have been keen to rack up the goals this time around.
The 19-times English champions weathered a lively start by City, during which Mario Balotelli sent a good chance flying well over the bar, before catching City and in particular keeper Joe Hart by surprise in their first move forward.
Winger Ashley Young set up Rooney, who struck a tame shot that Hart appeared to think was going wide but that trickled, almost in slow motion, into the bottom corner.
City's problems were compounded when captain and centre back Vincent Kompany winced his way off the field with just over 20 minutes on the clock.
The champions failed to learn from the opening goal and were once again caught out by a swift United counter-attack as Antonio Valencia and Rafael combined well on the right to cross to Rooney who was unmarked in space with another easy finish.
Mancini sent on Carlos Tevez seven minutes into the second half, taking off the ineffectual Balotelli who looked unimpressed with the decision as he headed down the tunnel, and the arrival of the former United striker had a swift impact.
Just after United had been unfortunate not to kill off the game with a third when Van Persie smashed a shot against the crossbar and Young's rebound was ruled offside, City got themselves back into the game.
First Tevez, then David Silva forced United keeper David de Gea into excellent saves before it was third time lucky as Tevez found Toure who slotted home to ignite a sense of belief among home fans and a sense of urgency among his team mates.
Silva went close with a shot that was deflected on to the bar with just over 10 minutes remaining as City continued to push.
Instead it was United who got the happy ending when Van Persie stepped up to take a free kick with just a few seconds remaining in the game and sent it past Hart via a deflection off the boot of Samir Nasri.
An exciting match was marred by the sight of bloody gushing down the face of Ferdinand after he was hit while celebrating the goal.
"What you saw happened to Rio should not happen on a football pitch," Van Persie said. (Reporting by Sonia Oxley; Editing by Justin Palmer)