A goal up and in control of the opening stages of the second half, Arsenal looked to be sapping energy and belief from Tottenham Hotspur in the north London derby.

But then a moment of madness struck, with the already booked Francis Coquelin diving in on Harry Kane and getting himself sent off.

Momentum swung to the home side and the Gunners were soon behind, only to fight back and claim a 2-2 draw. However, it will be seen as a huge chance surrendered and Arsène Wenger admitted Francis Coquelin was warned at the break.

“We told him at half-time because he had a yellow already,” the boss said to BT after the match. “We have big regrets because it looked like we were in control when we went to 10 men and that’s the regret of the day. Overall it’s difficult to take.”

LONDON, ENGLAND - MARCH 05: Arsene Wenger (3rd L) Manager of Arsenal watches Francis Coquelin walking off the pitch after his red card during the Barclays Premier League match between Tottenham Hotspur and Arsenal at White Hart Lane on March 5, 2016 in London, England. (Photo by Shaun Botterill/Getty Images)
Francis Coquelin trudges to the tunnel after receiving his second yellow card. (Photo by Shaun Botterill/Getty Images)

Even more frustrating for Arsenal is the fact that Spurs midfielder Eric Dier could’ve seen red too when the scores had been levelled at two a piece. The England international had already been booked and clearly tugged Olivier Giroud back on the halfway line. A free-kick was given, but no second yellow.

“I think Dier deserves a second yellow as well and that could have changed the game,” Wenger added, but didn’t want to make excuses for his side. “Overall we have to look at ourselves on that.”

Had Michael Oliver sent off Eric Dier the game could’ve been turned on its head once more: after the equaliser Arsenal were on top even a man down, who knows what may have happened if it was 10 on 10 for the closing stages?

Alas, we’ll never know.