Defender Gabbia rose highest to thump home Tijjani Reijnders' free-kick in the 89th minute and give Milan a Serie A win which pulls them out of a miserable early season slump.
Juventus were held to a 0-0 Serie A draw at Empoli on Saturday as Thiago Motta's side dropped more points after their goalless home stalemate against AS Roma before the international break.
Inter and AC Milan on Friday rejected the project to modernise and restructure the iconic San Siro stadium which they share, city mayor Giuseppe Sala announced.
Victor Osimhen has been sidelined by Napoli after the team he fired to Serie A glory just a over year ago left him both off their squad list for the 2024/25 campaign and potentially in season-long limbo.
Belgium striker Lukaku completed a permanent move to Napoli from Chelsea on Thursday, ending a long period of limbo with the Blues.
Inter Milan thrashed Atalanta 4-0 on Friday to move provisionally top of Serie A, while Torino snatched a late 1-0 win at Venezia to continue their positive start to the campaign.
The futures of Napoli striker Victor Osimhen and England international Ivan Toney are set to dominate the final day of the European transfer window on Friday as Chelsea continue their frenzied pursuit of new signings.
Napoli have signed Romelu Lukaku from Chelsea, the Serie A club announced on Thursday, ending the Belgium striker's extended period in limbo with the Blues.
Poland goalkeeper Wojciech Szczesny on Tuesday announced he was retiring from football at the age of 34 less than two weeks after the end of his contract with Juventus.
Roma slid out of the Serie A top four by the slimmest of margins as they lost 3-1 to Atalanta in Bergamo on Monday.
Thousands of joyous Napoli supporters greeted the team early Monday as they returned from their victory over Juventus, which brought the prospect of a historic Serie A title within touching distance.
Giacomo Raspadori smashed in the stoppage time decider to claim a huge win at Juve which pushed Napoli 17 points clear at the top of the table, sweeping aside disappointment at being knocked out of the Champions League by AC Milan midweek.
Romelu Lukaku shot Inter Milan to a 3-0 win over struggling Empoli on Sunday with his first Serie A goals from open play since the opening day of what has been a difficult return season in Italy.
Juventus' 15-point penalty for illicit transfer activity was revoked on Thursday but the spectre of sanction did not disappear completely after Italy's highest sporting court ruled that the case should be re-examined.
Juventus await on Wednesday to see whether their 15-point deduction for illicit transfer activity will stand as Italy's highest sporting court examines an appeal which could have a huge impact on their season.
Leaders Napoli were held to a goalless home draw by relegation-threatened Hellas Verona in Serie A on Saturday as Luciano Spalletti's side finished winless for the third time in their last four games in all competitions.
Napoli took another step closer to ending their 33-year wait to win the Serie A title after they came away from Lecce with a 2-1 win on Friday thanks to a bizarre own goal from Lecce defender Antonino Gallo.
Juventus have been ordered to close part of their stadium for their next home Serie A match against Napoli by an Italian sports judge after Inter Milan striker Romelu Lukaku was racially abused during Tuesday's Coppa Italia semi-final.
Milan have 51 points, one ahead of fourth-placed Inter Milan, and are four behind second-placed Lazio. Napoli are 20 points clear at the top