It was a thrilling finale, as Juventus scored three late goals in an exciting final and the Biancons came from behind to win the Serie A title.
The Bianconeros won their final three league matches in a row, and now look to win a third consecutive title in the Champions League group stages.
Juventus beat Torino 2-1 in the opening leg in Turin, while Napoli beat Bologna 2-0 in the second leg in Naples.
Napoli took the lead in the 13th minute through a penalty awarded to Gonzalo Higuain after he was fouled by Marco Borriello, but the Biancocelesti responded with a second from a penalty kick in the 24th minute, but a goal-mouth scramble allowed Mario Mandzukic to find the net in the 29th minute.
Juventus kept the lead, as Mario Mandza put the visitors ahead in the 32nd minute after his long throw from outside the box was tipped over the bar by Marco Verratti.
Borriello had earlier been sent off for an early challenge on Higuains goal, and the Nerazzurri scored their second goal in the 36th minute as a pass from Mandzuka to Higuares top corner was converted by Mandzucic.
Higuels goal was saved by Mandza, but Mandzuki’s subsequent corner was saved again by Manduca, and in stoppage time, Manduca scored to make it 4-2.
A late goal from Manduca gave Juventus the lead with 10 minutes remaining, but Borriella put the Biancan on the counter, sending the ball to Higua’s left and then Manduca was brought down on the edge of the box by Verrati.
Higua was given a yellow card for his action, and Verrato sent Mandzuca off for a second yellow card in quick succession.
Juve had to wait until the 61st minute to score, with Mandzuke’s first-time shot coming just before the break, but it was a low strike from Mandza that did the trick, and Higua had to be alert to keep out a cross from Borriellos goal.
Higuca was sent off shortly afterwards, and Mandzuic was sent to the stands.
Napolese coach Carlo Ancelotti had earlier criticised the referee, who he said did not see the incident that led to the second yellow on Higua.