MISSED the match? Catch up via beIN SPORTS CONNECT | 2-WEEK free trial
The hosts ended Juventus's eight-match winning run without conceding in the league emphatically to move 10 points clear at the top of the table.
Juve had gone on a remarkable run of form since losing to AC Milan in early October, but its defence was finally breached by Victor Osimhen with 14 minutes played.
Osimhen turned provider by playing in Khvicha Kvaratskhelia for Napoli's second at Stadio Diego Armando Maradona, but Angel Di Maria pulled one back before half-time having earlier hit the bar with an effort.
However, Luciano Spalletti's side pulled clear through another goal from Osimhen, either side of strikes from Amir Rrahmani and Elif Elmas, to put one hand on the Scudetto.
Napoli edged in front when Wojciech Szczesny palmed Kvaratskhelia's acrobatic attempt into the path of Osimhen for a simple finish from close range.
Di Maria sent a dipping effort against the crossbar, but Kvaratskhelia doubled Napoli's lead with a composed finish after Bremer's error allowed Osimhen to play his team-mate in.
Juve gave itself a lifeline through Di Maria's low finish past Szczesny after exchanging passes with Arkadiusz Milik, though Napoli should have cut out the danger.
Meret did brilliantly to prevent Rrahmani putting into his own net and that proved an even bigger save when the same player fired in on the half-volley from a corner.
The hosts were out of sight with 65 minutes gone as, after more sloppy play from Bremer, Kvaratskhelia and Osimhen again linked up for the latter to header across Szczesny.
Elmas, brought on at half-time for the injured Matteo Politano, added a fifth for Napoli with a shot that deflected in off Alex Sandro to round off a five-star showing.