Arsenal surprised everyone with a relentless performance in the opening 45 minutes of their match against Tottenham Hotspur.It’s impossible to write the Gunners off but they were understandably considered the underdogs heading into the game, even if they were playing in front of their own fans.But the Gunners were positive from the off, playing Spurs at their own game by pressing high up the pitch and forcing mistakes.And Arsene Wenger’s side went in 2-0 ahead at half-time through goals from Shkodran Mustafi and Alexis Sanchez.There was controversy surrounding the first goal, with Spurs fans furious at referee Mike Dean for two reasons.Davinson Sanchez was penalised for a foul outside Tottenham’s area. It appeared soft, mind, Alexis Sanchez going down under the centre-back’s challenge.There was more misery to come for Spurs when Mustafi headed Mesut Ozil’s resulting delivery home. The German’s effort was superb and left Hugo Lloris no chance, but he did appear to be offside.

It was 2-0 minutes later, Alexandre Lacazette teeing up Alexis Sanchez to score his second league goal of the season from close range.

There were questions asked of whether Lacazette was offside, too.

Both goals prompted a tweet from Joey Barton which has caused a stir.

The former Manchester City midfielder asked the question of whether both goals should have been disallowed, producing a mixed reaction from his followers.

“Both goals look slightly offside? 2-0 Arsenal... 🤣 #justsayin,” Barton wrote.

Here’s how fans on Twitter reacted.

Arsenal would go on to record an impressive victory against their rivals, their first in the league at the Emirates Stadium in a north London derby since 2013.

Ozil, in particular, was fantastic, prompting Arsenal supporters to get the club to sort out his contract situation. 

The German doesn't always do it in the big matches but he was excellent today, earning the man of the match award.