By London correspondent Tony Hughes

Diego Costa is a “petulant baby” and was lucky to escape a red card for his role in Gabriel’s sending-off as Arsenal’s clash against Chelsea grew heated before half-time, according to Rio Ferdinand.

Costa was the clear instigator in clashes with, first, Laurent Koscielny and then Gabriel but received only a yellow card while the Arsenal centre-back was sent off just before the break as he retaliated to the Chelsea man’s provocation.

TV pundit Ferdinand was unimpressed with Costa’s conduct and believes referees need to take a firmer stance with the striker.

“He’s acting like a petulant baby,” the former Manchester United defender told BT Sport. “He’s a ticking timebomb waiting to go off. He’s a fantastic player but he has to get back to playing football.

“He should have been sent off. It was clear. Referees need to deal with him properly and get a grip.”

Costa initially grappled with Koscielny, swiping his hand across the defender’s face, raising his arm and then chest-bumping the Frenchman to the ground.

Gabriel raced to support his team-mate and referee Mike Dean responded by giving yellow cards to both the Brazilian and Costa.

In the follow-up scrap, Gabriel responded to further provocation from Costa by aiming a kick at his opponent.

Dean handed the Gunners centre-half a red card within a minute and the defender had to leave the pitch.