While Tottenham players raged at a free kick they felt should never have been given at the Emirates, Arsenal were busy concentrating on the matter in hand.

Shkodran Mustafi planted a powerful header in off the post – against some rather tepid Eric Dier defending it has to be admitted – a minute after referee Mike Dean penalised Davinson Sanchez for fouling Alexis Sanchez.

Only it wasn’t a foul. It was great defending in a one-on-one situation and if it WAS the foul Dean awarded, a yellow card should have been given.

The referee’s assistant then did his best to deflect the attention away from Dean by failing to hoist his flag when Mustafi looked offside – albeit a borderline decision.

But by the time that first goal went in, Arsenal should have been down to 10 men. Granit Xhaka’s brutal challenge on the in-full-flight Moussa Sissoko deserved far more than the fatherly chat Dean administered on 22 minutes and it took Xhaka’s THIRD offence to finally get a yellow card.

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And that challenge on Dele Alli was another nasty one that should have seen him sent off.

Dean cannot be held responsible for another dodgy assistant decision for Arsenal’s second goal but the damage had been done by Mustafi’s opener.

Dean clearly got that wrong, combining a poor decision with a baffling one by not booking the Tottenham Sanchez. Surely it’s all or nothing.

But before thousands of Spurs fans quite rightly point to that key moment, manager Mauricio Pochettino would have been livid at the return of traditional Tottenham defending which just about gifted the Gunners that opener.

They switched off and are just as culpable as Dean – and Pochettino will know that…