Premiership round-up: Ruud van Nistelrooy hit a second-half winner for Manchester United at Bolton Wanderers to cut Chelsea's lead to seven points after the champions were held 0-0 at Birmingham.
Van Nistelrooy, starting from the bench again despite netting the winner against West Ham in midweek, converted Louis Saha's cross on 79 minutes to seal a 2-1 win at the Reebok Stadium and breathe new life into the title race. Saha had cancelled out Kevin Davies's opener for Bolton.
With six games to play, Chelsea have 79 points from 32 games with United on 72. Third-placed Liverpool (64) play away at West Bromwich Albion in a late kickoff.
Elsewhere, fourth-placed Tottenham Hotspur had Michael Dawson sent off in a 3-1 defeat at Newcastle United while Thierry Henry scored twice in Arsenal's 5-0 demolition of Aston Villa, who are being dragged into the relegation dogfight.
At the bottom, Portsmouth's third successive win, 3-1 over Fulham at Craven Cottage, gave the south coast side hope of escaping the drop. Bottom side Sunderland drew 2-2 at Everton and will be relegated if West Brom defeat Liverpool.
Chelsea manager Jose Mourinho was unhappy with another unconvincing display away from home, his side have won just one from their last five on their travels.
"I am concerned, I want to win every game, I'm not happy with the performance and result," he told Sky Sports. "We did not deserve to win the game, Birmingham deserved a point . . . they showed great spirit. I have to praise the way they fought.
"It's (the title) in our hands. The important thing is we keep winning our matches at home and we will be champions again."
Birmingham, third from bottom and reeling from shipping 10 goals in their last two games in league and Cup, defended competently and produced the game's best moment when Olivier Tebily forced Petr Cech into a fingertip save from long range.
Chelsea almost stole the points at the death but Argentine Hernan Crespo wasted two good chances while defender Ricardo Carvalho headed over.
The leaders also had two goals ruled out, Mourinho lamenting the decision to nullify Asier Del Horno's 50th minute header after Carvalho, in an offside position, was deemed to be active.
"We scored a goal . . . it was not offside. It was a clear goal according to the rules. I don't want to say more about it because every single word I say in this country the next day is a nightmare."
