The result lifted Manchester City above Chelsea in the standings, on goal difference after six games, but there was a greater significance to the victory.
Tuchel's team beat Manchester City three times last season -- including in the Champions League final.
Chelsea is set to have goalkeeper Edouard Mendy and midfieder N'Golo Kante fit to start the Champions League final against Manchester City on Saturday.
Manchester City vs Chelsea: UEFA meeting with British government on Champions League final at Wembley
UEFA was meeting virtually with the British government to discuss the logistics of using Wembley for the Champions League final.
The British government is advising supporters not to travel to Turkey because of the new restrictions.
Chelsea manager Conte defended his cautious approach despite his side failing to register a shot on target against Manchester City.
Chelsea's fourth defeat in five league games left Conte's reigning EPL title-holders five points adrift of the top four.