Already sitting atop the Serie A table after six matches, Antonio Conte’s men wasted no time in strengthening their position by taking the lead after a remarkable 25 seconds.
Already becoming a fan favourite in Campania, Scott McTominay received the ball from Lukaku and turned inside Alberto Dossena, before arrowing his shot back across goal and into the bottom corner.
Despite conceding the fastest goal of the Serie A season so far, Como were undeterred from going about their original game plan, and powerful efforts from Gabriel Strefezza and Nico Paz both flashed just wide of the mark.
Having calibrated his sights with that first attempt, Paz was extremely unlucky to see his next long-range drive cannon away off the inside of the post.
Napoli may have not previously conceded in any competition since August, but they were unable to withstand the immense pressure applied by Como in the run-up to half-time.
Maximo Perrone shifted it out to Strefezza on the edge of the area, and the Brazilian fired beyond the reach of Elia Caprile, who was beaten for the first time in Napoli colours.
Conte must have had some stern words for his players during the break because they came out with renewed purpose and stole back the lead within just a few minutes of the restart.
They surged into the box after a loose pass from Marc-Oliver Kempf, and Mathias Olivera was taken down by Sergi Roberto, giving Lukaku the chance to bury it down the middle from 12 yards.
Tempers flared after that, and Como were fortunate that Strefezza was spared a red card and that Napoli weren’t awarded another penalty after Alberto Moreno pushed Khvicha Kvaratskhelia.
Despite a strong overall performance, Como didn’t do enough to deserve an equaliser in the final stages, and the scoring instead went the other way.
Lukaku bookended his night with another assist, fending off Kempf to play through substitute David Neres, who slid his shot under Emil Audero.
A sixth win in seven since an embarrassing opening day defeat to Hellas Verona places Napoli firmly in the driving seat in Serie A, while a decent display did little to hurt Como’s credentials as Fabregas looks to embed his distinctive style of play.
Flashscore Man of the Match: Romelu Lukaku (Napoli)
