Juventus stopped Inter Milan from replacing Napoli at the top of Serie A on Sunday by beating their fierce rivals 1-0 and moving into Italy's Champions League positions.
Francisco Conceicao made sure that Napoli would stay two points ahead of Inter by crashing in the winning goal 16 minutes before the end of an entertaining contest in Turin.
Portugal attacker Conceicao netted his fourth goal of the season in all competitions after brilliant work from Randal Kolo Muani to give Juve a third straight league win.
Juve are in fourth place, ahead on goal difference from Lazio who had done wasteful Inter a favour by holding Napoli to a 2-2 draw in Rome on Saturday.
But Napoli stay at the summit with Antonio Conte's team and Inter facing off in Naples in a fortnight, a match which could well be key to the destination of the Scudetto.
Juve now turn their attentions to Wednesday's return leg of their Champions League play-off with PSV Eindhoven, with Thiago Motta's side leading the tie 2-1 following the first leg in Turin.