Edinson Cavani scored a hat-trick of headers to help Napoli beat Juventus 3-0 on Sunday and stay in the second position with four points behind Serie A leaders AC Milan.

Cavani netted twice in the first half and scored his and Napoli's third early in the second half as Walter Mazzarri's side overtook Lazio and inflicted the second defeat of 2011 on Juve.

Cavani scored his first goal in the 20th minute. A cross from Christian Maggio from the right teed up the Uruguayan perfectly and Leonardo Bonucci's attempted clearance on the goal line was in vain.

Amauri almost levelled immediately but De Sanctis made an excellent one-handed save to deny him. From the resulting corner, Juve thought they had levelled when Luca Toni headed the ball in, but the referee rather harshly halted play for a foul on De Sanctis by Juve's new signing.

On chances, Juve could have been 2-1 up, yet they slipped 2-0 behind when Cavani headed in his second in the 26th minute. This time, Andrea Dossena was the provider with a cross from the left and another header from Cavani left Marco Storari with no chance.

Amauri was denied again by De Sanctis early in the second half as the visitors continued to pose the greater threat. But Cavani only needed an inch as he completed a hat-trick of headers in the 53rd minute, diving low at the far post to nod in Marek Hamsik's cross.