Updated - Inter missed a chance to go top of Serie A when they were held 0-0 by champions Juventus in a physical Derby D'Italia while Gonzalo Higuain gave resurgent Napoli a 2-1 home win over leaders Fiorentina.
Higuain struck in the 75th minute, two minutes after Nikola Kalinic had pulled Fiorentina level, with his sixth league goal of the season to give the hosts their third win in a row.
Lorenzo Insigne had put Napoli in front less than one minute into the second half as they followed up a 2-1 win over Juventus and 4-0 demolition of AC Milan with another fine performance.
Marcelo Brozovic hit the bar in the first half for Inter and Sami Khedira struck the post in the second for Juve in a match littered with free kicks and eight yellow cards at San Siro.
Surprise package Sassuolo won again when a controversial penalty converted by Domenico Berardi and Simone Missiroli's close range goal set them on they way to a 2-1 win over Lazio, who replied through Felipe Anderson.
Fiorentina lead with 18 points from eight games, one ahead of AS Roma, who beat Empoli 3-1 on Saturday, and Inter.
Napoli, Sassuolo and Lazio are joint fourth on 15 while Juve, champions for the last four seasons, are languishing in 14th place with nine points.
Genoa overcame Chievo 3-2 with a stoppage time goal by Panagiotis Tachtsidis despite playing for the last 35 minutes with 10 men after Blerim Dzemaili was sent off.
Leading 2-1 when the Swiss was dismissed, Genoa were pegged back when Sergio Pellisier scored with a back-heeled volleyed in the 77th minute, only for Tachtsidis to turn in Oliver Ntcham's pass at the death.
Luca Paganini and Federico Dionisi scored twice in two minutes to give Serie A debutants Frosinone their second victory of the campaign as they beat Sampdoria 2-0.
A close-range goal by Franco Vazquez gave Palermo a 1-0 win at bottom club Bologna and Atalanta overcame Carpi 3-0.
DEFENCE-SPLITTING PASS
Napoli's match against Fiorentina came to life at the start of the second half when Insigne ran on to a defence-splitting pass and curled his shot wide of Ciprian Tatarusanu.
Napoli nearly had a second goal when Raul Albiol's header hit the bar but Fiore levelled when Kalinic ran on to Josip Ilicic's ball over the top, outsmarted two defenders and placed his shot past Pepe Reina with the outside of his foot.
Napoli went straight back in front when Higuain won possession in midfield, played a one-two with Dries Martens, broke clear and slotted his shot just wide of Tatarusanu.
Inter and Juventus created plenty of chances amid the bickering and fouling in the first half and the best effort came from Brozovic, whose curling shot from an improbable angle was tipped on to the bar by Gianluigi Buffon.
Juve took control in the second half and had their first shot on target when Juan Cuadrado's effort went through Samir Handanovic's legs and into the side-netting.
The visitors should have scored when Alvaro Morata laid the ball off to Khedira but his close-range effort struck the foot of the post.
Ivan Perisic blasted a free kick just over the bar late on for Roberto Mancini's Inter who have failed to win in their last three games, having started with fives wins on the trot.