Arsenal manager Arsene Wenger has called on the Football Association to punish Chelsea striker Diego Costa for his display during Saturday's 2-0 defeat to the champions at Stamford Bridge.
Costa tangled with Laurent Koscielny prior to half-time - appearing to strike the defender in the face - and then became embroiled in a row with the Frenchman's defensive partner Gabriel, who was sent off for kicking out at the Chelsea striker.
Santi Cazorla was dismissed in between goals from Kurt Zouma and Eden Hazard as Wenger endured another difficult day against old foe Jose Mourinho.
Asked about Costa's behaviour, Wenger added: "He can do whatever he wants and anyone who responds to him gets sent off.
"It's unacceptable his behaviour - if you look at the pictures what he does to Koscielny before he pushes him down, he hits him in the face before the throw.
"He always get away with it and honestly it's surprising. I don't understand Mike Dean's decision at all, not why Diego Costa stays on the pitch.
"Gabriel is sent off - okay I accept he hasn't to react - and after that on their first goal I couldn't see a free-kick [in the build-up]."
Cazorla's dismissal was prompted by a second yellow card for a late tackle on Cesc Fabregas but it was Costa's antics that enraged Wenger, who remains with just one career win over Mourinho.
On the subject of punishment for Costa, Wenger added: "That's the least they could do but he will do the same again next week and get away with it. He is always provoking and he uses the naivety of Mike Dean.
"Look at the pictures, it tells you a lot on the slow motion. Before the cross comes in he hits him. You expect that sort of game, we were not surprised, but you expect the referee to make the right decision.
"I don't want to judge overall but today I think it is surprising he got away with what he did. I don't want to judge Mike Dean as I don't watch all the games he referees
"For me it has nothing to do with strength, it is just making the right decision. That's all you want. "
