Paulo Dybala scored two goals, taking his tally to 10 in six league games, to lead Juventus to a 4-0 win over self-destructing neighbours Torino and maintain their perfect start in Serie A on Saturday.
Napoli also notched up their sixth straight win, beating SPAL 3-2 after Faouzi Ghoulam's late goal saw off a brave challenge from their promoted opponents.
Napoli, last season's top scorers, have hit 22 goals already and lead champions Juve on goal difference with both sides on a maximum 18 points.
Juventus had little trouble in dispatching Torino in the Derby della Mole as their opponents gifted them the opening goal and had a player sent off before the half hour.
Torino defender Lyanco set the tone in the fourth minute when he sent a misplaced back pass towards his own goal and was saved only by goalkeeper Salvatore Sirigu's desperate sliding clearance.
The visitors were in more trouble in the 16th minute when midfielder Tomas Rincon was dispossessed by Miralem Pjanic who slipped the ball to Dybala for the Argentine to fire Juve into the lead.
It got even worse for Torino when Daniele Baselli, having already been booked, flew wildly at Pjanic with his knees raised and was dismissed with only 25 minutes gone.
The game effectively ended as a contest when Pjanic swept in Juan Cuadrado's pass five minutes before halftime.
Alex Sandro headed the third from Pjanic's corner in the 57th minute and Torino kept the score down only thanks to a string of outstanding saves from Sirigu.
He was eventually beaten for a fourth time when Dybala got clear of the Torino defence in stoppage time to dink the ball over the 30-year-old.
Napoli had to come from behind on their way to a club-record eleventh consecutive league win.
Pasquale Schiattarella gave SPAL a shock lead in the 13th minute but Lorenzo Insigne equalised one minute later.
Jose Callejon headed Napoli in front in the 71st minute only for SPAL to hit back seven minutes later when Federico Viviani curled in a free kick.
Napoli refused to give up and Ghoulam settled matters with a fine solo effort, the Algerian running at the SPAL defence and cutting inside to finish with his right foot.
Two goals from Stephan El Shaarawy helped fourth-placed AS Roma to a comfortable 3-1 win at home to Udinese after Edin Dzeko had opened the scoring for last season's runners-up.
Diego Perotti missed a penalty for Roma before Jens Stryger Larsen scored a last-minute consolation for Udinese.
(Dzeko 12, El Shaarawy 30, 45) Udinese 1
(Stryger Larsen 90)
(Schiattarella 13, Viviani 77) Napoli 3
(Insigne 14, Callejón 71, Ghoulam 83)
(Dybala 16, 90+1, Pjanic 40, Alex Sandro 57) Torino 0