AC Milan started the game against Napoli strongly. They kept possession of the ball and have controlled the tempo in the first half for most of the time. Stefano Pioli's team missed a few important chances.
Here is the starting lineup of the Rossoneri at home:
4-2-3-1: Maignan; Calabria, Kjær, Tomori, Hernández; Bennacer, Tonali; Saelemaekers, De Ketelaere, Krunić; Giroud
As for Napoli, here are the choices of Spalletti, who was not on the bench as he was disqualified:
4-3-3: Meret; Di Lorenzo, Rrahmani, Kim, Mário Rui; Anguissa, Lobotka, Zieliński; Politano, Raspadori, Kvaratskhelia

The second half of the game started differently however, with Pioli replacing Davide Calabria who did defend well against Khvicha Kvaratskhelia. But, he was booked and it seemed that the gaffer did not want to risk him and he put Sergino Dest in to replace him (Edit: According to Milan News, Calabria was replaced at half-time due to muscle fatigue). That, unfortunately, did not work very well as his intervention on the Georgian's foot inside the box area meant a penalty for Napoli after a VAR review. Former Inter player, Matteo Politano, converted it against Mike Maignan at around the 55 minute mark.

Milan, though, obviously never gave up and kept attacking and the answer came minutes later by the man for the big occasions: Olivier Giroud after an assist from the flying French full-back Theo Hernandez. The French connection paid off well and it was game on for either side from the 69th minute.

At the 78th minute, Napoli found the second goal which delivered them the three precious points thanks to the substitute Giovanni Simeone who got his head in on Mario Rui's cross. The ball was slotted in the bottom corner. AC Milan remained faithful to their attacking ways and attitude of never giving up and came so close to equalising. Kalulu hit the crossbar and couldn't score. Luck was on Napoli's side tonight.
The unbeaten streak ends for the AC Milan team. Napoli remain the team yet to beat for Milan at the San Siro after so many years. It is not the end of the world, however, the season is still long, and hopefully the squad will regroup, analyse the loss together and focus on what's coming in the future. The game ended 1-2 in favour of the visitors.