Thomas Tuchel suffered their second straight 1-0 loss as Juventus claimed victory over Chelsea in the Champions League on Wednesday.
After losing to Premier League title rivals Manchester City at home to Chelsea on Saturday, Federico Chiesa scored the only goal of the game straight after half-time to give Juve points.
Juve have had a rough start to the season under new boss Massimiliano Allegri, who sits 10th in Serie A, but have made it past Europe.
Juve were content to allow Chelsea to take possession in the first half, with Thomas Tuchel's men enjoying 72% of the play in Turin. But despite dominating the ball, Chelsea struggled to create chances and open the home side.
The only shot on target for both sides in the opening 45 minutes came from Romelu Lukaku, who hit a left-footed effort from Marcos Alonso's corner routine in Wojciech Szczeciny after just seven minutes.
The best start for the home team came for Chiesa, with the forward expertly swinging Antonio Rudiger and bursting into the box before pulling a shot from Edouard Mendy's far post.
But it was Juve who scored the first goal of the game - and it came just 10 seconds after the restart. Federico Bernardeschi fed Chiesa inside the field, and the striker skillfully lifted his shot into the ceiling of the net.
Juve should have made it two when Adrian Rabiot cushioned a ball in the box en route to Bernardeschi, but he somehow fired over the bar with the goal at his mercy.
Lukaku had a chance to level up when fed by substitute Ross Barkley, but was shot down by the Belgian international after turning Leonardo Bonucci.
Chelsea almost snatched the draw in the 95th minute but Kai Havertz took the lead on the bar.
Later, Tuchel said he felt his team had lost its mental sharpness even before the Champions League holders stepped onto the pitch.
"We had a great training session yesterday," Tuchel told reporters. "We were absolutely fast and looked very refreshed and very hungry, ready to come back [from defeat to Manchester City].
"I think it's very difficult to find the rhythm against a team defending so deeply, it was the complete opposite in Manchester City's game.
"The big difference was that we made big mistakes that eroded our confidence. This morning I could tell it was different. We weren't as mentally refreshed as we were in training yesterday. I don't know why "
Tuchel's team did not make a single attempt on target against City over the weekend, but the German insists he is not worried about the lack of attack threat.
"We were short on runs, we were struggling to find our rhythm and maintain that structure of belief," Tuchel said.
"Maybe it's a shooting problem, because if you don't shoot you don't score. But if you play against a team that is so deep-seated like today, it's hard to take shots. We'll learn."
The win over Chelsea was Juve's third consecutive win in all competitions, as the Serie A team moved to the top of Champions League Group H on six points.
"Usually, sailors always find a way out in a storm," Allegri said. "Tonight we played a good match against the European champions.
"There's no turning back, let's just take six points and be happy. [League] championships are another thing.
"Tonight the team understood that against the other side that doesn't allow you to take possession, you have to adapt and match defensively. I never got angry, the defense was perfect."