The reigning champions dominated a strangely passive and conservative Chelsea in a meeting between two sides widely expected to compete for the Premier League title this season.
Gabriel Jesus’ 53rd-minute effort took a touch off Jorginho to beat Chelsea keeper Edouard Mendy – but few could question City’s right to win against the team that defeated them in last May’s Champions League final, and the victory margin should have been far more emphatic.
Aymeric Laporte should have scored but slid a shot wide from inside the six-yard box, while Jesus almost added a second when Thiago Silva cleared his effort off the line.
Mendy also made two crucial saves from the outstanding Jack Grealish.
It was the ideal start to a crucial week for City and manager Pep Guardiola, who will travel to Paris St-Germain in the Champions League this week before facing Liverpool at Anfield the following Sunday.