Theo Hernandez’s first-half strike gave AC Milan a sixth win from seven Serie A matches with a 1-0 victory over Napoli.
The reigning champions made a bright start but Hernandez’s goal changed the complexion of the match for a Napoli side low on confidence.
Khvicha Kvaratskhelia and Matteo Politano hit the woodwork for the visitors after the break but they could not find an equaliser to prevent a seventh league defeat of the season.
Napoli created the first big chance of the game when Kvaratskhelia skinned Matteo Gabbia and sent a drilled delivery into the area but Giovanni Simeone could not guide his effort beyond goalkeeper Mike Maignan.
Walter Mazzarri’s side continued to make most of the running in the opening stages but AC Milan took the lead against the run of play through a devastating counter-attack as Rafael Leao slipped Hernandez through on goal and he whipped the ball past Pierluigi Gollini at the near post.
Milan had an opportunity to make it two moments later when Leao found himself with space outside the box but his bending effort was diverted away from the top corner by Gollini.
Napoli’s frustrations were compounded when Piotr Zielinski picked himself up after being fouled on the left of the area but wastefully sent a free-kick out for a goal-kick.
The visitors had the first chance of the second half when Politano tried his luck from 20 yards but his effort did not quite get the curl needed to nestle in the bottom corner.
Hernandez could have doubled his tally in style when a corner fell to the defender inside the area and his clever back-heeled volley flew into Gollini’s gloves.
Napoli responded with another chance, this time Kvaratskhelia cut in from the left but hit a rather tame strike into Maignan’s grasp.
The visitors gifted possession to Yunus Musah and offered Milan a chance to give themselves some breathing space but Leao struck wide of the far post.
Napoli began to run out of ideas and were limited to long-range efforts, the next being Andre-Frank Zambo Anguissa’s shot from 25 yards which flew comfortably wide of the target.
The visitors’ flurry of second-half chances did not stop and they came within inches of levelling when Jesper Lindstrom’s cross was deflected onto a post by Jan-Carlo Simic as Milan held on.