Manchester City responded perfectly to their disappointing Champions League defeat to Paris St Germain, with Pep Guardiola's side coming from behind to beat Chelsea thanks to goals from Josko Gvardiol, Erling Haaland and Phil Foden.
The Citizens handed debuts to new signings Abdukodir Khusanov and Omar Marmoush from the start, and Khusanov endured a nightmare as he gifted Chelsea the opening goal.
Man City's £33.6m new signing headed the ball back to the goalkeeper but failed to look and allowed Nicolas Jackson to steal the ball. Jackson then set up Noni Madueke to score into an empty net.
Gvardiol had two good chances to equalise for Man City before taking a third just before half-time. Ilkay Gundogan's cross was well-placed for Matheus Nunes to break into the box, whose shot hit goalkeeper Robert Sanchez and bounced out. Gvardiol dived at the right moment to tap home the equaliser.
Man City were the better team in the second half and finally took the lead through Erling Haaland. From a long pass from goalkeeper Ederson, Haaland headed the ball past centre-back Trevoh Chalobah. Chelsea goalkeeper Sanchez inexplicably rushed out and the Norwegian headed the ball into the net.
Foden sealed the victory in the final minutes for the home team from Haaland's assist.
The win over Chelsea was only City's sixth in 20 games in all competitions, but the three valuable points were enough to take Guardiola's side back into the top four and potentially turn things around.
Just three days after a heartbreaking defeat to PSG, City's position in the Premier League table will be a relief to Guardiola, especially after he brought on two new signings and saw his side fall behind.
On the contrary, Chelsea dropped to sixth place in the Premier League table. Remember, not long ago, coach Enzo Maresca's team was predicted to compete for the championship.
The Blues have now won just one of their last seven games and their plans have been disrupted in worrying fashion. The high defensive line that initially caused City problems was eventually exposed when Madueke was exposed by Gvardiol on too many occasions. Haaland and Foden then easily beat Chelsea's offside trap to score.
In fact, the Blues' reaction to falling behind was almost non-existent, a surprising response given that the result could have represented a crucial turning point in the race for European qualification.