Ruslan Malinovskiy's late effort consigned Juventus to a 1-0 defeat at Atalanta and struck a blow to their chances of qualifying for next season's Champions League.
Only three minutes remained of Sunday's Serie A contest when Malinovskiy's effort deflected past Wojciech Szczesny to secure the points for Atalanta, who leapfrog Juve into third place in the table.
The Bianconeri were without the injured Cristiano Ronaldo and his absence was acutely felt as Andrea Pirlo's side lacked a cutting edge in attack.
Juve have now drawn three and lost one of their games in Serie A this season where Ronaldo has been absent.
Atalanta had an early shout for a penalty when Luis Muriel was nudged over by Juan Cuadrado inside the box, but the referee waved away the appeals.
Federico Chiesa, who later limped out injured, registered Juve's first meaningful effort when he struck a shot from distance that flashed past the post.
Atalanta carved open the Juventus defence midway through the first half with a slick passing move, but Matteo Pessina fired wide from a good position.
The Bianconeri moved up a gear before the interval and Alvaro Morata almost capitalised on some sloppy Atalanta defending only for Joakim Maehle to clear the Spain striker's dinked effort off the line.
Atalanta enjoyed a spell of possession after half-time without testing Szczesny, although the Juventus goalkeeper breathed a sigh of relief on the hour mark when Duvan Zapata's curling effort went over the bar.
Zapata went close again with 20 minutes left when he got on the end of a Josip Ilicic cross but could only direct his header wide of goal.
Morata looked Juve's most likely source of a goal and he forced Pierluigi Gollini to save well when he tried to side foot the ball past him from a tight angle.
However, it was Atalanta who stole the points late on when Malinovskiy received the ball from a quick corner and struck a low shot from outside the area, which deflected off Alex Sandro and wrongfooted Szczesny.
What does it mean? Pirlo under pressure
Before this encounter Juventus had scored at least two goals in each of their last seven away games against Atalanta in Serie A.
But without Ronaldo they struggled to break down Gian Piero Gasperini's side, as they managed 11 shots in the contest but only one of them was on target.
The Bianconeri have now won only one of their last seven against Atalanta across all competitions (drawn four, lost two) and the pressure is growing on Juve head coach Pirlo after this defeat.
Towering display from Toloi
Rafael Toloi was immense at the back for Atalanta as he marshalled the home side's defence with authority, used the ball well in possession and led by example.
Toloi made three tackles, three clearances and won 100 per cent of his nine duels. He had more touches (79) and made more passes (64) than any other Atalanta player
Dybala fails to fire
Asked to fill Ronaldo's boots Argentina forward Paulo Dybala endured a tough game as he failed to make an impact in attack.
Dybala failed to register a single shot on target, won 40 per cent of his duels, and had just two touches inside the box before he was substituted in the 68th minute.
Key Opta Facts:
- Atalanta have beaten Juventus in Serie A for the first time since February 2001.
- Juventus have five defeats in the first 31 league matches for the first time since the 2010-11 campaign.
- Malinovskiy has been directly involved in seven goals (two goals, five assists) in his last four Serie A appearances.
Juventus face Parma at home in Serie A on Wednesday while Atalanta head to Roma the following day.