Marek Hamsik moved onto 99 Serie A goals for Napoli as Maurizio Sarri's side moved four points clear at the top of table with a 5-0 thrashing of Cagliari in Sardinia.

With Juventus' clash against Atalanta postponed due to snow in Turin on Sunday, Napoli were able to increase their advantage over the Bianconeri a day later.

Cagliari display were picked apart by the leaders, with Allan and Lorenzo Insigne their tormentors in-chief.

Allan's marauding run just before the half hour brought the game's opening goal, his pinpoint cross met by Jose Callejon, the Spain international guiding the ball past Alessio Cragno.

Napoli continued to attack their hosts and as half-time beckoned they double their lead, Dries Mertens making amends for an earlier miss with his 16th goal of the season.

Sustained pressure in Cagliari's penalty area eventually saw the ball drop to Insigne and his dangerous delivery was touched beyond Cragno by the feintest of finishes from Mertens.

Just after the hour Hamsik edged closer to a century of top-flight goals for the Partenopei with a curling effort from 18 yards out.

Insigne led a swift counter attack down the Napoli right before playing in his captain, Hamsik making no mistake to stand on the brink another milestone.

He was denied the chance to reach three figures, though, as Insigne stepped up to convert a 72nd-minute penalty after Leandro Castan had handled.

Full-back Mario Rui put the icing on the cake for the visitors in the final minute with a superb free-kick.