Napoli have missed the chance to move top of Serie A after Bologna survived a late comeback to beat the title contenders in a five-goal thriller.
I Rossoblu took the lead after only 14 minutes at the Stadio Renato Dall'Ara as Mattia Destro reacted first to Amadou Diawara's cross before tucking the ball past Pepe Reina.
Gli Azzurri had chances to take the lead themselves through Lorenzo Insigne and Jose Callejon, but struggled to respond after going behind.
Instead, they conceded another after Luca Rossettini headed home Franco Brienza's corner from close range.
Just before the hour mark, Gonzalo Higuain was denied by Antonio Mirante as Napoli tried to get themselves back into the game.
However, the match was over as a contest when Destro finished off a fast break with his second of the afternoon.
Bologna could have scored a fourth late on when Anthony Mounier blazed a shot over from only a few yards out.
Higuain pulled one back on 87 minutes, but the visitors appeared to be running out of time to earn a result.
The Argentine then scored another in the 90th minute to set up a grandstand finish, but Bologna held on for their third win in five games.