Chelsea manager Jose Mourinho felt Fernando Torres' harsh dismissal cost his team victory against Tottenham at White Hart Lane.
Gylfi Sigurdsson's first-half opener was cancelled out when John Terry headed in Juan Mata's free-kick.
But Chelsea were left holding on for a 1-1 draw after Torres received a second yellow card with 10 minutes remaining following an innocuous aerial collision with Jan Vertonghen.
Asked if the result was fair, Mourinho told BT Sport 1: "I don't think it was.
"I think they were better in the first half but not much better, they didn't create so many chances.
"In the second half, there was only one team. The team was very, very strong until the moment the referee made a mistake, a big mistake that had a big influence on the result.
"The referee is not guilty, the player (Vertonghen) is guilty - he pretended that Fernando had a big contact on him and the referee went on trust.
"At that moment we were much better, they were in big trouble. We were winning everything in midfield and going in waves of attack, (Andre) Schurrle had just had a chance that normally he has to score.
"It leaves a bad taste because we should win."
Opposite number Andre Villas-Boas said of Torres' dismissal: "It was a difficult decision for the referee, both players were going for the ball and he decided Fernando was over the top."
Reflecting on his team's performance, Mourinho's former assistant said: "It was a good game in general and I'm extremely happy with the performance.
"Our second half wasn't as good as we wanted and Chelsea did well to score from the set-play.
"With their pressing we lost fluidity and they did well to come back in the game.
"Both teams had chances, the chances were spread. We had a chance to (lead) 2-0 before half-time and that would have been the killer."
The fractured relationship between the two Portuguese managers had dominated the build-up to the game but Mourinho said: "Between men - not children - this is not public. It is between us.
"What you want and the people want, we gave, which is a very good football match."