Juventus were surprisingly held to a 1-1 draw by struggling Lecce in Serie A on Saturday as Matthijs de Ligt's disappointing start to his Bianconeri career continued.
De Ligt has been at fault for several goals since his 75 million euro ($85 million) transfer from Ajax in the offseason and the 20-year-old gave away the penalty that led to Lecce's equalizer.
"I thought the movement of his arm was natural," Juventus coach Maurizio Sarri said. "But with the new rules it's almost impossible for a defender to avoid certain things."
Paulo Dybala had scored from the spot to give Juventus the lead.
Inter Milan can move top of Serie A, a point above Juventus, if it beats Parma later.
Lecce moved two points above the relegation zone ahead of the rest of the weekend's fixtures.
Cristiano Ronaldo was rested for the match and Juventus struggled to create goalscoring opportunities.
Gonzalo Higuain thought he had given Juve the lead in the 15th minute but his goal was ruled out for offside.
Juventus had a couple of penalty appeals in the first half but it was awarded a spot-kick after the break for a lunge by Lecce defender Jacopo Petriccione on Miralem Pjanic.
Dybala struck the ball into the bottom right corner to put Juventus in front, five minutes into the second period.
However, Lecce levelled just six minutes later with a similar penalty from Marco Mancosu following De Ligt's handball.
Federico Bernardeschi should have restored Juve's lead but he hit the post.
Higuain ended the match with his head covered in bandages after a clash with Lecce goalkeeper Gabriel left him bleeding from his forehead.
Juventus had used up their three substitutions so Higuain continued but the Argentina forward had to be stretchered off after the final whistle and has been taken to the hospital for tests.