It was an evening to forget for the Blues as a brace by James Maddison in the first half and goals from Pedro Porro and Brennan Johnson after the break won it for the visitors.
There was plenty of pre-match positivity with Pep Guardiola signing a new two-year deal earlier this week and Rodrigo showcasing his Ballon d’Or trophy just before kick-off.
And when the game started, City looked intent on keeping that feelgood factor going.
But a double by attacking midfielder Maddison on 13 and 20 minutes shocked the Etihad and put us on the back foot.
Porro made it three for Ange Postecoglou’s side on 52 minutes before Johnson fired home from a pinpoint cross by fellow sub Timo Werner just before the final whistle.
City remain second in the Premier League behind Liverpool, who we face next in the top-flight at Anfield a week on Sunday.