Juventus beat Napoli in a remarkable Serie A game as Kalidou Koulibaly’s injury-time own goal negated the visitors’ three-goal comeback.
The champions led 3-0 through goals from debutant Danilo, former Napoli striker Gonzalo Higuain and Cristiano Ronaldo’s first of the season.
But three summer signings scored to put Napoli level – Kostas Manolas, Hirving Lozano and Giovanni di Lorenzo.
That was in vain as Koulibaly shinned a deep free-kick past his own keeper.
Juve, who have won the last eight titles, clearly lacked the presence of captain Giorgio Chiellini – likely to be out for several months with an anterior cruciate ligament injury – at the back, with £67.5m summer signing Matthijs de Ligt making a shaky debut.
Juventus boss Maurizio Sarri did not take charge against his former club as he recovers from pneumonia, although he was at the Allianz Stadium watching the game.
How Juventus took control
The contest looked over after 62 minutes, with Juventus very impressive in the first half especially.
Former Manchester City defender Danilo had to come on to replace the injured Mattia de Sciglio, and 29 seconds into his debut he scored after converting Costa’s cross to finish off a swift counter-attack.
Higuain then doubled the lead brilliantly as he turned Koulibaly before smashing the bouncing ball past Alex Meret with the outside of his foot. Ronaldo added a third in the second half as he finished another Costa cross.
The Napoli comeback
Former Roma defender Manolas’ header from Mario Rui’s cross in the 66th minute looked a mere consolation.
But two minutes later they had real hope when Lozano, on his debut following a move from PSV Eindhoven, slotted in from Mario Rui’s cross to become the first Mexican to ever score in Serie A.
Juventus winger Costa had a good shot tipped on to the woodwork by Meret – and that save looked crucial moments later.
The dream looked set to become a reality for Napoli, who have finished second to Juventus in three of the past four seasons, when Di Lorenzo, a summer signing from Empoli, beat De Ligt to the ball to scramble home a free-kick.
There was one more Napoli goalscorer, but sadly it was into his own net as Koulibaly, scorer of a famous winner against Juve in April 2018, got his angles wrong and rifled Paulo Dybala’s deep free-kick past Meret.