Juventus moved closer to a fifth successive Serie A title with a 4-1 derby victory at Torino, while Gianluigi Buffon set a new league record for the longest run without conceding a goal at 973 minutes.
Buffon's historic run was ended by Andrea Belotti's penalty after 10 clean sheets, but Juventus eased to victory on Sunday.
First-half goals from Paul Pogba and Sami Khedira were followed by a brace from substitute Alvaro Morata, although Khedira was shown a late red card for dissent.
Juve's top goalscorer Paulo Dybala, who returned from a calf injury to start, lasted only half an hour before limping off but Massimiliano Allegri's side have now won 19 of their last 20 league matches, a run that started with a 2-1 win against Torino at the end of October.
Gonzalo Higuain took his league goals tally to 29 with a brace as Napoli stayed three points behind Juventus by coming from behind to beat Genoa 3-1.
Tomas Rincon's long-range strike put the visitors into a shock 10th-minute lead but Higuain struck twice in the second half and Omar El Kaddouri added gloss to the scoreline in injury-time.
Fiorentina missed the chance to close the gap on third-placed Roma in the race for the final Champions League qualification place as they were held 0-0 at Frosinone.
AC Milan drew 1-1 at home to Lazio after Carlos Bacca cancelled out Marco Parolo's early header, leaving both sides looking unlikely to qualify for European football next season.
Carpi moved out of the relegation places with a 2-1 win at bottom side Verona, Kevin Lasagna's free-kick giving his side a vital three points in their survival battle.
Luigi De Canio's first game as Udinese coach ended in a 1-1 draw at Sassuolo after Duvan Zapata's opener was followed by Matteo Politano's header and Chievo moved into the top half of the table with a 1-0 win at Sampdoria.
Atalanta broke their run of 14 league matches without victory with a 2-0 home win against nine-man Bologna, who had Ibrahima Mbaye and Daniele Gastaldello sent off.