A Juventus team minus a host of stars including Cristiano Ronaldo were made to wait to wrap up an eighth consecutive Serie A title as they slipped to defeat at SPAL.
Juve boss Max Allegri rested a number of big-name first team players with an eye firmly on Tuesday nights Champions League quarter-final second leg in Turin, with that tie finely poised at 1-1.
But the decision backfired, as despite taking the lead through teen sensation Moise Kean, Juventus slipped to a 2-1 defeat at the Serie A strugglers.
The defeat kept Juve on 84 points at the top of the league table from 32 games played – 20 points ahead of second-placed Napoli, who have played a game less.
While Juventus coronation is inevitable, they faced just their second league defeat of the season at the hands of SPAL, who started the game just four points ahead of the relegation zone.
Juve boss Allegri handed a debut to 17-year-old defender Paolo Gozzi Iweru, who lined up alongside Andrea Barzagli – 20 years his senior – at the back.
Top scorer Ronaldo was not named in the matchday squad, while Leonardo Bonucci began on the bench and fellow veteran Georgio Chiellini was again absent as he struggles to return from a calf injury.
Argentinian Paolo Dybala and Italian youngster Kean started up front in the absence of Ronaldo and with usual strike partner Mario Mandzukic also rested.
Kean opened the scoring when he diverted a Joao Cancelo shot past Emiliano Viviano and into the SPAL net on 30 minutes.
The strike took 19-year-old Kean to six league goals for the season, and past Juve legend Alessandro del Pieros previous record league tally for a teenager for a single season in Serie A.
But Kevin Bonifazi leveled for the hosts four minutes after the break, before SPALs 37-year-old number 10 Sergio Floccari poked home from eight yards with just over quarter of an hour to play.
It was The Old Ladys second league defeat all season, following their 2-0 away at Genoa in March – when they were also without Ronaldo.