Manchester United suffered a third major blow in eight days on Sunday when a 0-0 draw at Blackburn Rovers damaged their hopes of claiming a fourth consecutive Premier League title.
United, who went out of the Champions League on away goals to Bayern Munich on Wednesday, failed to break down a resolute Rovers side which means they remain stuck behind leaders Chelsea having played a game more.
Chelsea have 74 points from 33 games while United, whose 2-1 defeat at home to Chelsea last weekend cost them top spot, have 73 from 34 games. Arsenal are still in the hunt with 71 points from 33 games.
United manager Alex Ferguson made six changes to the side who started the ultimately fruitless 3-2 win at home to Bayern on Wednesday with Dimitar Berbatov and Federico Macheda up front and Ryan Giggs and Paul Scholes also included.
However, with leading scorer Wayne Rooney missing after re-injuring his ankle on Wednesday, United were toothless as for the seventh time this season they dropped vital league points in the match following midweek Champions League fixture.
Rovers' Paul Robinson was the busier of the two goalkeepers, the pick of his saves being the one that denied Antonio Valencia early in the second half, but the home side looked comfortable for most of a scrappy encounter.
United's problems increased late on with defender and England World Cup captain Rio Ferdinand dislocating a finger and then limping through the final minutes with what looked like a groin injury.
Wolverhampton Wanderers took another step towards ensuring their top flight survival with a 0-0 draw against Stoke City that leaves them six points above the relegation zone.
The battle for fourth spot continues later on Sunday with Manchester City, currently fourth, at home to Birmingham City and sixth-placed Liverpool needing a victory over fellow Europa League semi-finalists Fulham to stay in touch.