There were shades of Luciano Spalletti's Scudetto-winning side on show at Mapei Stadium as Francesco Calzona's Azzurri orchestrated a scintillating display to sweep aside a sorry Sassuolo.
Having fallen behind to Uros Racic's early opener, Napoli dusted themselves down and struck twice in as many minutes to turn the tables.
The first was a beautifully worked goal: Giovanni Di Lorenzo threaded a low ball into the box and Frank Anguissa's deft backheel found Amir Rrahmani, who gratefully fired in the equaliser.
A near identical move 120 seconds later conjured up the second. This time Di Lorenzo picked out Matteo Politano, who teed up Victor Osimhen to score.
The Nigerian made it a brace before the break when a poor pass allowed Politano to set him up again.
The second half was barely minutes old when last season's top scorer completed his hat-trick. Khvicha Kvaratskhelia made the most of another defensive mix-up to hand his team-mate the easiest of finishes.
Five minutes later the Georgian decided to go it alone, cutting inside from the left flank and drifting past several Sassuolo shirts before unleashing an unstoppable shot inside the far post.
He wasn't done there. With a quarter of an hour left on the clock, Giacomo Raspadori's corner found Kvara on the far side of the box. The winger's first effort was blocked but he got another bite of the cherry and made no mistake with his second attempt.
A resounding victory and half a dozen goals will provide a timely confidence boost for the Azzurri going into next Sunday's home game against Juventus.
Sassuolo 1-6 Napoli (HT 1-3)
Scorers: Racic 17, Rrahmani 29, Osimhen 31, 41, 47, Kvaratskhelia 51, 76.
SASSUOLO: Consigli; Pedersen, Tressoldi (Kumbulla 77), Ferrari, Doig (Missori 56), Racic (Volpato 56), Matheus Henrique, Bajrami (Defrel 77), Thorstvedt, Lauriente, Pinamonti.
Coach: Bigica.
NAPOLI: Meret; Di Lorenzo, Rrahmani (Natan 62), Ostigard, Mario Rui, Anguissa, Lobotka (Dendoncker 80), Traore (Zielinski 77) Politano (Raspadori 62), Kvaratskhelia, Osimhen (Simeone 77).
Coach: Calzona.
Referee: Chiffi (Padua).
