Juventus won at Inter Milan to maintain the pace at the top of Serie A, while AC Milan notched their fourth straight league victory.
Juventus retained their two-point advantage at the top of the table and piled even more misery on Claudio Ranieri's Inter Milan with a win at the San Siro.
Mirko Vucinic put the Bianconeri in front in the 12th minute, but Maicon levelled for the hosts in the 28th minute.
Claudio Marchisio restored Juve's advantage in the 33rd minute and he was unlucky not to earn a penalty just before half-time.
Inter were unable to find a way back into the game and succumbed to their fifth defeat in nine games to risk dropping into the bottom three of Serie A this weekend.
Earlier, in-form AC Milan inflicted a 3-2 home defeat on Roma to move to the top of the standings for a few hours.
Zlatan Ibrahimovic put the visitors ahead in the 17th minute before Nicolas Burdisso equalised shortly after.
Alessandro Nesta restored AC Milan's lead at the half-hour mark.
Ibrahimovic gave Milan a two-goal cushion with his second goal of the game in the 78th minute.
Roma substitute Bojan reduced the arrears three minutes from time but Milan held on for their fourth straight league victory.
Catania moved level on points with Napoli with a 2-1 win at the Stadio Massimino.
Edinson Cavani put Napoli ahead in the first minute, but the Sicilians turned the game around with goals from Gonzalo Bergessio and Giovanni Marchese.
To add insult to injury, Napoli ended the game with 10 men with Mario Santana controversially sent off late in the first half for a second bookable offence.