After a quiet start to the first half, Napoli took the lead inside 18 minutes through marauding centre-back Giovanni Di Lorenzo, whose deflected shot from the edge of the box wrong-footed Simone Scuffet and dribbled into the opposite corner.
Cagliari reacted well, as Paulo Azzi cut inside and unleashed a powerful strike that had to be tipped around the post by Alex Meret just moments later.
After a delay midway through the half, Meret was on hand again to deny Roberto Piccoli’s downward header from close range, as the visitors maintained their half-time advantage.
Cagliari continued to threaten an equaliser early in the second half, as Meret saved Sebastiano Luperto’s diving header before brilliantly tipping Razvan Marin’s long-range strike onto the crossbar.
However, Napoli still possessed a threat themselves on the counter, and the deadly Khvicha Kvaratskhelia slotted cooly past Scuffet to double the Partenopei’s lead.
A horror mistake at the back then allowed the Georgian to set up Romelu Lukaku, who accepted the gift and stroked into the bottom corner for a quickfire third - he has now scored seven goals in eight games against Cagliari.
There was even time for a fourth for the visitors in stoppage time, as Alessandro Buongiorno headed home from a corner to inflict more misery on the hosts, who failed to score for the third time already this season, as they dropped down to second-bottom with only one win in 27 H2Hs against Napoli.
In contrast, the visitors now boast three consecutive league victories under Conte, who maintains a 100% winning record against Cagliari boss Davide Nicola after four meetings.
Flashscore Man of the Match: Khvicha Kvaratskhelia (Napoli)
