In a match played behind closed doors at a virtually empty Etihad Stadium, City put in a highly confident display as they took advantage of a hapless Gunners team who lost two players to injury in the first half before seeing David Luiz sent off early in the second half.
Raheem Sterling scored the opener just before the break, then Kevin de Bruyne's penalty and Phil Foden's tap-in confirmed an easy win for the Blues.
Eric Garcia, who had started alongside Aymeric Laporte in the centre of defence, came off on a stretcher after a sickening collision with Ederson late in the game.
