Allegri side fightback to earn their first Serie A victory of the season against Spezia.
Centre-back Matthijs de Ligt scored the winner from a corner six minutes after Federico Chiesa’s equaliser.
Spezia had produced their own comeback from a goal down through,
Emmanuel Gyasi and Janis Antiste, after Moise Kean’s low strike into the bottom corner gave Juventus a 28th-minute lead.
Victory moves Massimiliano Allegri’s side up to 12th in the table.
Having failed to win any of their first four games for only the fourth time in the club’s history.
Kean’s first Juventus goal since rejoining from Everton in August temporarily relieved some of the pressure on the visitors.
But Gyasi levelled with a looping strike five minutes later.
And, after a couple of good saves by goalkeeper Jeroen Zoet from Paolo Dybala at the end of the first half.
Antiste’s deflected shot threatened to extend Juve’s miserable start.
Chiesa, rewarded for his persistence as the ball broke kindly for his goal, led the Juventus fightback.
De Ligt stabbed home with 18 minutes remaining before a nervous-looking Juventus held on for a valuable first three points of the campaign.