Arsenal manager Arsene Wenger claims that striker Diego Costa should have been sent off twice in the defeat to Chelsea.
Wenger watched as his Arsenal side failed to capitalise on the poor form of Jose Mourinho's men, falling to a 2-0 defeat at Stamford Bridge. However, the story of the match was when Costa and Gabriel tussled after the Spain striker had bumped into Laurent Koscielny.
Costa and Gabriel were both handed yellow cards for their part in the scuffle, but Gabriel then lifted his foot into Costa once the dust had settled and received a straight red card.
Santi Cazorla was then given his marching orders for a second yellow card late on and Wenger was furious with referee Mike Dean.
"I would not like to be Mike Dean tonight," Wenger told the BBC after the match. "Costa twice should be sent off. He hits him [Koscielny] in the face in purpose. In every game he has aggravation and he gets away with it because of the weakness of the referee. We knew before the game he is only looking at that.
"Gabriel should not have responded at all but the two sending offs for us and Costa staying on the pitch is a shame."
While Wenger accepted Gabriel had been guilty for not controlling himself there was no doubt of the main culprit.
"He [Costa] can do what he wants, he stays on and everybody else who responds to him has to be sent off. I think it is unacceptable his behaviour,'' said Wenger.
"If you look well at the pictures what he does to Koscielny before he pushes him down he hits him in the face and the throat, he always gets away with it.
"It is surprising and I don't understand Mike Dean's decision at all, not on the sending-off -- why does Diego Costa stay on the pitch and Gabriel sent off?
"Okay I accept he has not to react at all. Gabriel is guilty for getting involved of course, he should not have responded at all, but Koscielny had no choice.
Wenger added: "We expect that kind of game and were not surprised, but you expect the referee to make the right decision. I don't deny Gabriel is sent off, he deserves it, but he (Costa) goes down well.''
Asked if he felt retrospective action from the Football Association was called for, Wenger replied: "That is the least they could do, but he will do the same again next week and the week after and he always gets away with it.
"For me, it is always in provocation and he uses well the naivety of Mike Dean today. Look at the pictures, it tells you a lot on slow motion. Before the cross comes in he hits him.
"The fact is surprising that Diego Costa got away with what he did, that we go into half-time with a red card and he stays on the pitch.
"They (referees) are professional people, and they have to make the right decision.''