Chelsea manager Jose Mourinho indicated that he was unhappy with referee Phil Dowd after his side were denied all three points by Robin van Persie's 94th-minute equaliser for Manchester United in a 1-1 draw at Old Trafford.
The Premier League leaders went in front when Didier Drogba, deputising for the injured Diego Costa, headed home a corner early in the second half.
But after Chelsea defender Branislav Ivanovic had been sent off for a second yellow card following a foul on Angel Di Maria, Van Persie slammed home a rebound from the free-kick to level.
Mourinho made it clear that he was not happy with that decision and also felt Chelsea should have had a first-half penalty when Ivanovic went to the ground under a Chris Smalling challenge from a first-half corner.
"The red card, I could see it coming," he said. "If I have to speak about the second yellow I have to speak about lots of things -- the penalty that Ivanovic should have been given, the accumulation of yellow cards, the throw-ins. I know I speak always with my heart and get in trouble."
At his postmatch news conference, Mourinho said: "I have come from the flash interviews. I did five, and in all five the first question was my comments on the referee.
"I told them no comment -- because when five ask the same thing I don't need to answer.
"I prefer just to say that in my opinion, from where I was and reading the game, my feeling is that we had a good first half and a fantastic second half.
"To come here and play the way we did and not to be happy with the point -- because we are not -- shows clearly how good we were and how well we are playing at this moment."
Asked again about his feelings on Dowd's performance, Mourinho said: "You know I cannot speak. Some [managers] can, some don't. I am one of the ones that cannot, because you know what happens to me when I speak.
"So I won't. I will speak about the game, which I thought was good. I thought Manchester United were good, but Chelsea were very good. We played very well. I'm so happy with my players."
Mourinho praised his team for a second-half performance that had seemed increasingly likely to bring all three points, saying: "The second half was much better. From the start of the first half, we showed we wanted to win. In the second half, we didn't give them chances they wanted."
After a weekend that saw both Manchester City, who lost at West Ham, and Liverpool, held at home by Hull, drop points, Mourinho added: "Of course I prefer to lead from the front. We are four points clear, so I can say at this moment that, next weekend, it won't matter about results -- we will be top of the league.
"I prefer to be in front rather than behind, obviously, because you have a little space for your mistakes -- or for the referees' mistakes."