Romelu Lukaku's 27th goal of the season helped Inter Milan extend their lead at the top of Serie A to 11 points with a 2-1 victory over Sassuolo.
Inter were ahead within 10 minutes when Lukaku headed home Ashley Young's cross to put his side in the driving seat.
They had to wait until 23 minutes from time to extend their lead when Lautaro Martinez rounded off a counter-attack, and although Hamed Traore pulled one back for the visitors with five minutes remaining, Sassuolo could not deny the home side a 10th successive league win.
Juventus had 43-year-old Gianluigi Buffon to thank as they beat Napoli to climb into third place in the table.
The veteran goalkeeper, deputising for Wojciech Szczesny, made a series of saves as his side secured a 2-1 home win to climb to within a point of second-placed AC Milan.
Cristiano Ronaldo, who had missed the target with an early header, fired the home side into a 13th-minute lead as he dispatched Federico Chiesa's cross.
However, it took fine saves by Buffon to deny first Giovanni Di Lorenzo and then Lorenzo Insigne an equaliser before substitute Paulo Dybala added a second 17 minutes from time.
Buffon was finally beaten by Insigne from the penalty spot in the final minute of normal time after Giorgio Chiellini had fouled substitute Victor Osimhen, but Juve saw out time to take the points.
In LaLiga, Roberto Lopez struck late as Real Sociedad climbed into fifth place after a 1-1 home draw with Athletic Bilbao.
Lopez smashed home an 89th-minute equaliser just four minutes after fellow substitute Asier Villalibre had headed the visitors in front.