Arsenal fell behind inside a minute to Pep Guardiola’s side through Sergio Aguero at the Etihad.
The Argentina international then went on to seal his hat-trick on the hour mark as City chase down Liverpool in the Premier League.
Aguero took his league tally to 13 for the season after scoring his third, but Arsenal fans have put two of their players in the spotlight for their involvement in the goal.
Whilst Aguero put the ball into the net, eagle-eyed fans saw club captain Koscielny trip over his German team-mate Leno, leaving fans fuming at two of their own players.
One fan said: “Koscielny and Leno hahahaha can we get the circus theme tune over the top of that please.”
Another added: “Koscielny falling over Leno and into the net just sums us up perfectly.”
“Seeing Koscielny fall over the goalkeeper making me laugh a lot more than it probably should do,” one said.
Before the game, pundit Graeme Souness had praised Unai Emery, who’s Arsenal side have now slipped behind Manchester United in the league.
“You don’t need to reserve judgement, he’s a good manager,” Souness said of Emery on Sky Sports.
“I think he’s done, with that group of players, really, really well.
“I think Arsenal for a long time have been a team that have promised so much but never delivered.”