Napoli and Juventus delivered club record winning streaks to maintain their Serie A title challenges on Wednesday, while Hellas Verona finally recorded its first victory of the season.
Gonzalo Higuain netted his 23rd goal in as many league games to help Napoli win at Lazio 2-0, and match the club record of seven successive league victories, set in 1987-88.
Napoli's win was marred by racist chants directed at visiting defender Kalidou Koulibaly from some of the Lazio fans, as well as other discriminatory chants, which led to the suspension of the game for four minutes in the second half.
"We should congratulate (referee Massimiliano) Irrati because the situation was becoming embarrassing, we were all upset for Koulibaly," Napoli coach Maurizio Sarri said. "I saw him after the game and he seemed calm to me. He's a profound lad, he will be upset, but will remain calm with the help of his teammates."
Lazio, which was punished last year for a similar offence, risks having to play two matches behind closed doors.
Juventus extended its run to 13 successive victories by beating Genoa 1-0 to remain two points behind Napoli.
"Historically, it has been hard for Juventus to play against Genoa," Juventus coach Massimiliano Allegri said. "We're coming from an intense period, and Sunday's win (4-0 at Chievo Verona) created a bit of euphoria. Tonight's match brought us back down to earth.
"I'm not interested at all in the record, I'm interested in focusing on the next match."
Fiorentina is six points further back after Mauro Zarate's stoppage-time goal snatched a 2-1 victory over Carpi.
Fourth-place Inter got back to winning ways by beating Chievo 1-0, while AC Milan continued where it left off in Sunday's derby win with a 2-0 victory at Palermo, with Carlos Bacca and M'Baye Niang on the scoresheet again.
At the other end of the table, Verona beat 10-man Atalanta 2-1 to end its worst streak; it was its first win in 23 matches. Verona's previous worst streak before this year was 13 matches without a win in 1989-90.
Verona is 10 points from safety after 17th-place Sampdoria drew against Torino 2-2.
Second-from-bottom Frosinone also won, beating 10-man Bologna 1-0.
Empoli rescued a 1-1 draw against Udinese.
Higuain, in the form of his life, had nine goals in five Serie A matches against Lazio, so it was no surprise when he opened the scoring midway through the first half.
He gathered Jorginho's ball over the top, played a swift one-two with Jose Callejon and fired past Lazio goalkeeper Federico Marchetti at the second time of asking.
Callejon got on the scoresheet himself three minutes later, beating the offside trap to run onto Lorenzo Insigne's marvelous ball over the top and chip Marchetti.
In Turin, the only goal of the game came after half an hour when Juan Cuadrado dribbled into the right side of area and his cross was deflected in by Sebastien De Maio.
There was bad news for Juventus as defender Patrice Evra went off injured in the first half and Martin Caceres was carried off in tears in the second.
Juventus forward Simone Zaza was shown a straight red card in stoppage time for a dangerous tackle on Armando Izzo.
Inter started 2016 top of the league but slipped down the table following two draws and two defeats, including Sunday's humiliating 3-0 loss to bitter rival Milan in the derby.
Chievo let in four goals in each of its two previous matches, and was dominated by Inter, which couldn't find the breakthrough, wasting chances, as well as being denied by an excellent Andrea Seculin, who was making his top-flight debut.
Mauro Icardi broke the deadlock minutes after the interval, slotting into the near side of the net for his 50th goal in 109 Serie A matches.