Manchester City were brought down to earth by a masterclass from Champions League holders Paris St-German at Etihad Stadium.
City – watched by former manager Pep Guardiola on his return to the club – were playing their first home game since being found guilty of breaching Premier League financial rules.
In an atmosphere of defiance from City's supporters, PSG stunned Enzo Maresca's side by powering into a three-goal lead by half-time.
Desire Doue opened the scoring in the 13th minute with a low shot past City keeper Gianluigi Donnarumma, before setting up the second with a perfect cross for Ousmane Dembele's header two minutes later.
PSG were tearing City apart, Vitinha adding the third after 32 minutes with a clinical finish after superb link play between Maghnes Akliouche and Warren Zaire-Emery.
Maresca made three half-time substitutions and City were a team transformed after the break, creating a host of chances before Erling Haaland pulled a goal back with a flicked header from Iliman Ndiaye's cross eight minutes after the interval.
City's hopes of a comeback were stopped in their tracks after 62 minutes when Donnarumma initially saved Akliouche's shot, only for it to drop behind him into the net.
City refused to yield, Haaland getting his second and seeing another effort miraculously kept out by PSG keeper Matvei Safonov - the one final act of drama coming when Donnarumma saved Ferran Torres' late penalty.