Cagliari 0-5 Napoli

Dries Mertens scored a hat-trick as Napoli ran riot with a 5-0 Serie A win away to Cagliari.Mertens was the hero in midweek as he secured Napoli's passage through to the last 16 of the Champions League, scoring the decisive goal in a 2-1 victory at Benfica.And the Belgium forward made it 13 goals for the season as Napoli extended their unbeaten run in all competitions to eight games.Napoli were on top from the opening exchanges, with Jose Callejon firing over and Marek Hamsik having his close-range effort blocked on the goal-line by Fabio Pisacane.Cagliari survived until the 34th minute when Mertens turned smartly past Luca Ceppitelli and buried his shot in the far corner of Marco Storari's net.Napoli doubled their lead on the stroke of half-time when Storari superbly tipped Lorenzo Insigne's header on to the bar but Hamsik volleyed the rebound home.In doing so, Hamsik became the only player to score at least five goals in each of the last 10 Serie A seasons.The second half was a cakewalk for Napoli as the Cagliari defence was cut open at regular intervals.Piotr Zielinski fired home from outside the box soon after the restart and Hamsik slipped Mertens through after 69 minutes for another tidy finish.Three minutes later Mertens completed his hat-trick - his second for Napoli - when he broke through unchallenged.The only downside for Napoli was an injury to defender Kalidou Koulibaly which forced him off in the first half.ends