Arsenal and Tottenham have one of the biggest rivalries in European football.
The two clubs have been battling for domination in north London since their very first fixture in 1909.
For decades, it was Arsenal who reigned supreme but in recent years, Spurs have begun to leave their mark on the capital.
The rivalry is always fiercely contested on the pitch and both sets of players know how much it means to get the win.
Supporters are always going back and forth with one another on social media too and even a summer without Premier League football hasn't stopped them tearing into each other.
It's not often we see big players get involved in these types of Twitter wars but on Thursday afternoon, Mesut Ozil just couldn't help himself.
One Tottenham fan posted an image of his side's squad photo ahead of their latest pre-season friendly, captioned 'Wait why tf was Özil in our team photo???'
The way the players were standing made it look like there was someone missing, so he was making a joke that the Gunners midfielder 'always goes missing' in games.
Clearly, his post caught the attention of Ozil, who replied: 'If you look closely... you can see your trophy cabinet... #YaGunnersYa.'
Ouch. Imagine tweeting a joke only to be absolutely ruined by an elite footballer who plays for your biggest rivals.
Unsurprisingly, Arsenal fans absolutely loved it and within an hour, Ozil's response had over 33,000 retweets and 80,000 likes.
Some are even calling for Unai Emery to hand him the captain's armband.
With Ozil schooling a Spurs fan on Twitter, it's been a pretty good week all-round for Gunners fans.
Arsenal impressed during their 2-2 pre-season draw with Real Madrid on Tuesday night, whilst they've also secured a loan deal for Dani Ceballos too. It could all be falling into place at the Emirates.News Now - Sport News