Man City ratings: Ilkay Gundogan pulled the strings and Kelechi Iheanacho scored but Pep Guardiola will be frustrated that another win slipped away.
Chances were tough to come by as PSV and Rostov finished deadlocked in a scoreless stalemate.
Arsene Wenger's team selection looked like a bit of a gamble when it was announced, but could hardly have been more successful in a big win at Basel.
A win would have seen PSG through as group winners, but they twice fell behind to their Bulgarian opponents.
Arsenal's Lucas Perez hit three goals inside the game's opening 47 minutes as the Gunners claimed first place in Group A.