Dries Mertens scored a hattrick to lead revitalised Napoli to a 5-0 rout at leaky Cagliari in Serie A on Sunday.

The Belgian broke the deadlock in the 34th minute when he scored with a shot on the turn before Napoli's inspirational captain Marek Hamsik turned in a rebound on the stroke of halftime after Lorenzo Insigne headed against the bar.

Midfielder Piotr Zielinski scored the third goal with a long-range shot six minutes after the break before Mertens completed a memorable afternoon in Sardinia by scoring two more goals within three minutes of each other.

He ran on to Insigne's pass and held off a defender before slotting the ball past Marco Storari in the 69th minute, then slipped the ball between Luca Ceppitelli's legs as he ran through the Cagliari defence to complete his hat-trick.

Napoli are fourth in the table with 31 points from 16 games. Cagliari are 12th but have the worst defensive record.

In a later match, Gonzalo Higuain again showed his killer instinct, scoring two expertly-taken goals as Juventus claimed a late 3-1 win at Torino after their less illustrious neighbours had scored first and dominated the game.