Chelsea manager Jose Mourinho claims Manchester United have enjoyed more than their fair share of luck this season.
United are nine points clear of the champions in the Barclays Premiership after their last-gasp 2-1 win at Fulham on Saturday, although Mourinho's side have a game in hand.
'This is a season in which United have had no injuries and every player is fine to play,' said the Blues boss, who also referred to Ryan Giggs' winner in the Champions League last week which French club Lille have appealed against.
'They go [to] the Champions League and have a disallowed goal for the opponent [Lille] and their goal is that goal.
'They go to Fulham and it looks like they deserve to lose and they win. They play at Tottenham, it's 0-0 and Cristiano [Ronaldo] dives, they get a penalty and win 4-0. It looks like everything is on their side, but that's football.
'I didn't see the Fulham game to be fair, but the information I have is it was completely undeserved. It's a game they could have lost and in the end they win it.
'In the Premiership all we can do is keep winning and see if the next step is to close the gap or to open the gap. If the next step is to close the gap and we can go from six points to four points, then everything is open.'
Mourinho also claimed Arsenal manager Arsene Wenger, who has won just the 2005 FA Cup since Mourinho came to England, was under less pressure than him to win trophies.
The Blues beat their London rivals in a Carling Cup final on Sunday marred by three red cards and a brawl.
He said: 'Arsenal have great boys. But I wouldn't be sad if a club gives me three, four, five years and tells me, `You don't need to win. You can lose Premiership after Premiership, and you have three, four, five seasons to build'. I wouldn't be sad.
'Since I arrived at Chelsea, they lost Premierships, they lost the Charity Shield to us, they lost the Carling Cup to us. I don't think they are winning a lot. Absolutely brilliant young boys, manager top, team with a great future. But they didn't win.'