Juventus have beaten holders Chelsea in the Champions League group stage on Wednesday.
The Italian side are struggling domestically but now sit top of Group H with six points from two games.
Federico Chiesa scored the game's only goal in Turin after he finished high past Chelsea keeper Edouard Mendy.
There were chances to increase the goals total for both sides, with Romelu Lukaku spraying a few opportunities.
Kai Havertz also had a glorious chance to equalise, but the German headed over with the last action of the game.
The Blues, who beat Manchester City in the final last season, dominated possession but were unable to score in Italy, and Thomas Tuchel was annoyed to cop a "easy goal".
"It is impossible when you're at this level to concede an easy goal as what we did tonight, especially in the first seconds of the second half," Tuchel said.
"We have to be able to defend this and be set up but we were punished and it was very frustrating."
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