Paul Merson questioned why Manchester City player Jeremy Doku did not receive a yellow card in the first half after he delayed the restart.
In a titanic clash at the top of the Premier League table, Arsenal travelled to Manchester in search of their first win against the defending champions since 2015.
It looked like that unenviable record was about to be extended when after just nine minutes, Erling Haaland fired the home team in front after splitting open a stagnant Gunners defence.
But out of the blue, new man Riccardo Calafiori pulled out a top-class goal, striking the ball with his left foot across Ederson and into the top corner from just outside the area.
Gabriel then found himself free two yards from goal after a whipped in Bukayo Saka corner to give his side the lead just before the break.
But six minutes into added time disaster struck, with Leandro Trossard being shown a second yellow card after it was deemed he had delayed the restart by kicking the ball away.
Speaking in the Sky Sports studio at half-time, Arsenal legend Merson pointed out how Doku avoided a booking for also delaying the restart earlier in the contest when he kicked the ball back into the Arsenal half with the referee then waving the game on.
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