Sir Alex Ferguson described referee Martin Atkinson's performance as "absolutely ridiculous" after Manchester United lost 1-0 at Chelsea and fell five points behind Carlo Ancelotti's Premier League leaders.
A bad-tempered match was settled by Chelsea's winner in the 76th minute, when John Terry and Nicolas Anelka rose to head a free-kick from Frank Lampard. TV replays suggest Anelka had the final touch, but Chelsea captain Terry was claiming it afterwards.
Ferguson was furious that Atkinson had not disallowed the goal for a foul by Didier Drogba on Wes Brown. The United manager was also upset about the award of the free-kick, for a foul by Darren Fletcher on Ashley Cole.
Wayne Rooney was seen mouthing the words "12th man" to Sky TV cameras as he left the pitch at the final whistle. Ferguson, who is already facing a charge of improper conduct over his comments about Alan Wiley's fitness after United's 2-2 draw with Sunderland last month, said: "Clearly Darren Fletcher has won the ball.
"He's never touched Ashley Cole who just jumped up in the air, and then Drogba has pulled Brown to the ground at the goal. The referee's position to make a decision there was absolutely ridiculous. He can't see it.
"There was a Chelsea player standing right in front of him and he doesn't even move. It was a bad decision, but what can you do? You lose faith in the refereeing sometimes. That's the way the players are talking in there. It was a bad one. That goal should not have been allowed."
Ferguson has criticised Atkinson before, for not giving United a penalty in an FA Cup tie with Portsmouth in March 2008.
Chelsea manager Ancelotti criticised United players for moaning too much to the match officials, after Fletcher mimed waving a card. The Italian said: "I think the United players protested a lot. I don't know why. I don't like this, for sure."
Ferguson claimed his side had had the better of a tense contest, and deserved to have won. "We've dominated the game and had great chances to win the match," he said.
"And that's our fault. Some of the football we played getting up to the box, and some of the chances in and around the box, and we should have finished them off, but you do need a break. We never got the break we needed."
Chelsea now boast a five-point lead over United, who have been champions for the past three seasons. Terry said: "It's exactly what we wanted – to be five points clear. It wasn't the best of games, but we deserved it. Another clean sheet. Even the attackers got back and defended for the team. That's what we want them to do and that's what they did."
Terry played despite newspaper reports yesterday that his father, Ted, 55, had been filmed selling cocaine in the toilet of an Essex wine bar.
Ancelotti said: "I don't know the story about John Terry. We spoke about the game, nothing else. I told him to block Rooney. And I think he did that very well."