Omer Atzili scored twice as Maccabi Haifa beat struggling Juventus 2-0 on Tuesday in Champions League Group H, pushing the Italian giants to the brink of elimination.
Juve are third in their group after four matches, equal on three points with Maccabi, who remain bottom despite their first win, and four behind Benfica and Paris Saint-Germain, who play later in the evening.
Juventus had suggested their form was improving as they beat the Israeli team in Turin last week, but lost to AC Milan on Saturday to slide to eighth in Serie A.
After the game Juventus president Andrea Agnelli expressed his dismay but repeated his support for coach Massimiliano Allegri.
"I'm ashamed of what's happening right now," said Agnelli to Sky Sport Italia.
"There is no one person culpable, it's not the coach's fault if we can't win a tackle. Allegri is going to remain coach of Juventus."
The hosts dominated the first half at the Sammy Ofer stadium and took the lead after seven minutes.
Atzili outjumped the visiting defence to meet a cross from Pierre Cornud, and although he turned his head away just before making contact, the ball struck his back. Wojciech Szczesny reached the ball but it crawled through his outstretched fingers and in off the post.
Maccabi poured forward. Tjaronn Chery hit the bar. Szczesny saved from Atzili.
The home team continued to dominate after Juventus midfielder Angel di Maria limped off with a thigh problem in the 24th minute.
Three minutes before half time, Atzili shaped to curl a left-footy shot inside the far post, but instead clipped it inside the near post with Szczesny rooted to his line.
Juventus managed their first strike on goal seconds before half time but Joshua Cohen saved low from Dusan Vlahovic's header.
Juventus pressed from the start of the second half and Cohen saved high from a Daniele Rugani header flying toward the top corner.
He later saved from wingers Juan Cuadrado and Arkadiusz Milik but Maccabi created late chances as they held on comfortably.
In their third appearance in the Champions League group stage, Maccabi claimed their second big scalp 20 years after their first.
In their debut campaign they beat Manchester United 3-0 at home in October 2002. They failed to progress then or on their second appearance in 2009-10.