Lowly Crotone put a dent in Juventus' bid to secure a seventh successive Serie A title by holding the leaders to a 1-1 draw on Wednesday.
Massimiliano Allegri's much-changed side appeared on course to record a 10th away win in their last 11 league outings after Alex Sandro's 16th-minute header broke the deadlock.
Meeting Douglas Costa's whipped cross from the left ahead of the near post, the Brazilian defender used the pace on the ball to angle it past goalkeeper Alex Cordaz and into the far corner of the net.
While never shifting out of second gear, Juventus appeared in complete control of proceedings until Simeon Nwankwo scored a spectacular equaliser in the 65th minute.
The striker's wonderfully executed bicycle kick secured Walter Zenga's strugglers an unlikely point in their battle to beat the drop, and potentially re-opened a title race that had threatened to become a procession.
While the Bianconeri still remain clear at the summit, Napoli's 4-2 home win over Udinese means the gap is down to just four points ahead of Sunday's pivotal clash between Italy's top two in Turin.
Allegri, who had warned his players against looking beyond Crotone in his pre-match news conference, unsurprisingly shuffled his pack, only Daniele Rugani, Blaise Matuidi and Paulo Dybala were retained in the starting XI, though the side on display only served to demonstrate their strength in depth.
Juve took the lead with their first attempt on target too, Costa’s excellent delivery from the left teeing up compatriot Sandro to flick the ball beyond Cordaz.
The home side had to wait until the 44th minute to call Wojciech Szczesny into action at the other end, though Gianluigi Buffon's understudy was alert enough to get down quickly to collect Nwankwo's left-footed effort.
However, Crotone - who had lost all three previous top-flight meetings between the clubs - posed far more problems for their illustrious opponents after the break.
Bruno Martella fired into the side-netting from a tight angle on the left in the early stages before Szczesny was required to snuff out a dangerous situation, smothering an indirect free-kick inside the penalty area after referee Michael Fabbri had judged the falling Medhi Benatia to have passed the ball to his goalkeeper when under pressure.
There was nothing the Poland international could do about the equaliser, though. After substitute Marcello Trotta's acrobatic attempt was blocked, Nwankwo succeeded where his team-mate failed, flashing his ambitious volley into the net.
Stunned into life by conceding, Juventus suddenly upped the tempo in search of a winner, only for Cordaz to deny them with two spectacular saves.
After flying high to his right to tip Matuidi's rising drive from distance wide, the Crotone captain clinched his team a famous draw by flinging himself across his goal to block Gonzalo Higuain's crisp volley.
