Fiorentina fell to a surprise 1-0 defeat at Cagliari as it lost ground in the race for a Champions League place, while AC Milan coach Clarence Seedorf's winning start in the Italian league ended on Saturday.
Milan was held to 1-1 at home by Torino.
Cagliari scored six minutes from halftime when Mauricio Pinilla blasted home from the penalty spot after Facundo Roncaglia tripped Marco Sau.
The home side could have doubled its tally in stoppage time as first Fiorentina defender Stefan Savic almost scored an own goal then Albin Ekdal's shot clipped the top of the upright.
Fiorentina new signing Anderson made his first start following a loan move from Manchester United but proved ineffective. The Tuscan team was missing leading strikers Mario Gomez and Giuseppe Rossi, who are out with long-term injuries.
Fiorentina remained three points behind third-place Napoli, which visits Atalanta on Sunday.
Later, Seedorf was looking to become the first Milan coach since Luigi Bonizzoni in 1958-59 to win his opening three Serie A games.
Milan, which was without the suspended Mario Balotelli, dominated but Torino took the lead in the 17th minute thanks to a wonderful solo effort from Ciro Immobile. He ran almost half the length of the pitch before feinting past Daniele Bonera and firing across into the bottom right corner for his 11th goal of the season.
Adil Rami scored his first for Milan since his move from Valencia to level matters four minutes after halftime. The France defender ran onto Sulley Muntari's short pass before unleashing a rocket shot into the left of goal.
Robinho thought he gave Milan the lead 10 minutes later when he curled Kaka's through ball into the far side of the net, but he was narrowly ruled offside.
"It's a really great emotion to score," Rami said. "It was four or five months that I didn't play, it was a difficult moment for me, it wasn't easy in my head. I'm lucky to have a strong character."
Rami was suspended by Valencia at the beginning of October after insulting his coach and teammates in a radio interview.
Elsewhere, Udinese snapped a run of four successive defeats to beat Bologna 2-0 in a relegation fight.
Udinese took the lead in the 15th minute when a somewhat soft penalty was awarded against Michele Pazienza for a nudge on Andrea Lazzari, and Antonio Di Natale fired Udinese in front, despite Bologna goalkeeper Gianluca Curci guessing the right way.
Nico Lopez sealed the result in stoppage time when he finished off a swift counterattack.
Udinese moved provisionally six points clear of the relegation zone. Bologna remained just a point off the bottom three.