Gonzalo Higuain scored twice as Napoli came from behind to beat AC Milan 3-1 and reinforce its bid for a Champions League place after Fiorentina's earlier victory over Atalanta in Serie A on Saturday.
Third-place Napoli remained three points ahead of Fiorentina, which won 2-0.
Adel Taarabt took less than eight minutes of his Serie A debut to fire Milan in front, racing half the length of the pitch before curling a wonderful finish into the bottom right corner.
Gokhan Inler levelled three minutes later with a deflected effort into the top right corner.
Higuain had an effort ruled marginally offside and Cristian Maggio hit the post as Napoli threatened to take the lead on several occasions.
The home side finally made the most of its opportunities 11 minutes after halftime when Higuain, who had been threatening all night, headed home a delightful cross from Inler.
The Argentine doubled his tally eight minutes from time to take his season tally to 16 in all competitions.
Shortly beforehand, Mario Balotelli broke down in tears on the bench after being substituted off following a below-par performance from the Italy striker.
It was Clarence Seedorf's first league defeat as Milan coach.
Also, Udinese beat Chievo Verona 3-0 in a relegation battle.
Josip Ilicic broke the deadlock in Florence in the 16th minute when he curled a superb free kick into the near top right corner from 25 metres.
Atalanta's hopes of getting anything from the match all but evaporated when it was reduced to 10 men nine minutes from time following Luca Cigarini's second booking.
Substitute Rafal Wolski sealed the match in the 86th, racing almost half the length of the pitch and holding off defenders before firing across into the bottom left corner for his first Serie A goal.
Udinese had lost four of its past five Serie A matches, while Chievo was without a win in its past seven, scoring only four goals during that period.
Chievo almost took the lead on the half hour when Cyril Thereau's back-heeled effort crashed off the base of the upright.
Udinese went in front in the 56th when Antonio Di Natale brought down Dusan Basta's pass and volleyed across into the bottom left corner for his third goal in as many matches.
Substitute Bruno Fernandes tapped home Roberto Pereyra's cross in the 74th and Emmanuel Badu added a third shortly before fulltime.
Udinese moved provisionally nine points clear of the relegation zone and eight points ahead of Chievo.