Napoli are aiming for their first Serie A title since Diego Maradona lifted the southern club to two Italian league trophies in 1987 and 1990.
After the win over Udinese on Saturday, Juventus have 41 points to their credit in Serie A 2021-22 points table, while toppers Inter Milan lead with 49 points.
Olivier Giroud scored AC Milan's only goal in the 14th minute to help his team move past the second-placed Napoli in Serie A.
Torino defeated Genoa 3-2 to move up to 10th in Serie A. Sampdoria beat Spezia 2-1 to take the 13th spot.
Juventus has only won three of its opening seven matches and sit eighth in the league. The former champions are already seven points behind leaders Napoli.
Ante Rebic scored a second-half hat-trick as AC Milan hammered Torino 7-0 in Serie A in the battle for a Champions League spot
Pirlo offered some tactical advice to his struggling Juventus players after they were held to a 2-2 derby draw by lowly Torino.
Juventus are surely out of the Serie A title race after they could only draw in a dramatic derby with city rivals Torino
Torino moved one point clear of the drop zone while Fiorentina was 12th.
Serie A leaders Milan could not find a way past Torino inside 120 minutes but prevailed on penalties in Tuesday's Coppa Italia last-16 tie.
Milan bounced back from their defeat to Juventus by overcoming Torino 2-0 at San Siro to take a four-point lead at the top of Serie A.
Nicolas Nkoulou had looked to have handed Torino a precious win in the Turin derby but Weston McKennie and Leonardo Bonucci had other ideas.
Gianluigi Buffon makes history with 648th Serie A appearance as Juventus goalkeeper passes AC Milan icon Paulo Maldini
AC Milan failed to bounce back from their derby defeat to Inter, as Andrea Belotti's late brace secured Torino a 2-1 win in Serie A on Thursday.