(CNN) -- Second-placed Juventus gave Italian leaders Inter Milan the chance to move seven points clear after suffering a 3-2 home defeat by Napoli on Saturday, with striker Amauri sent off late to rub salt in the Turin giants' wounds.
Jose Mourinho's Inter travel to struggling Livorno on Sunday on the back of a pulsating 5-3 victory against Palermo on Thursday night, and will be seeking to capitalize on their rivals' latest lapse.
The Bianconeri squandered a two-goal lead as Napoli went one better than the come-from-behind midweek draw at AC Milan to climb to fifth in the table on goal difference above Parma.
French striker David Trezeguet put Juve ahead in the 35th minute against the run of play when he headed Zdenek Grygera's left-wing corner past goalkeeper Morgan De Sanctis.
Sebastian Giovinco doubled the lead in the 54th minute after a mistake by Napoli defender Matteo Contini, but Marek Hamsik pulled a goal back five minutes later with his seventh of the season from Jesus Datolo's low cross.
Datolo leveled in the 64th minute when he pounced after keeper Gianluigi Buffon could only parry a header from German Denis and the rebound fell in his path.
Hamsik snatched the winner 10 minutes from time from Datolo's cross to give coach Walter Mazzarri a record of three wins in four league games since replacing the sacked Roberto Donadoni.
Amauri was sent off following a goalmouth melee as the game went deep into injury-time with Juve searching in vain for an equalizer.
AC Milan moved up into fourth place, six points behind city rivals Inter, with a 2-0 victory over Parma at the San Siro.
Striker Marco Borriello scored both goals after starting ahead of Filippo Inzaghi, with the resurgent Ronaldinho involved each time.
Borriello opened the scoring in the 12th minute after the Brazilian playmaker was given room to run at the defense and thread a deflected pass to his teammate, who slotted the ball through the legs of goalkeeper Antonio Mirante.
Thiago Silva almost made it 2-0 three minutes from the end when he headed against the crossbar from point-blank range, and Borriello killed off any doubt with a spectacular volley from Ronaldinho's cross three minutes into time added on.
The win was a boost for the team and coach Leonardo ahead of Tuesday's home Champions League clash with Real Madrid.