Hit: Gianluigi Donnarumma (AC Milan)
The sky is the limit for Gianluigi Donnarumma, who's been exceptional between the sticks for AC Milan this season. Before this game, he had conceded just seven goals and kept three clean sheets. Even though Donnarumma couldn't add to his clean sheet tally at the San Paulo, the young Italian pulled off numerous saves to keep Napoli at bay.
The excellent Donnarumma kept out Bakayoko, Di Lorenzo and Mertens in quick succession when the game was still goalless in the first half.
In the second half, Donnarumma prevented Elmas from scoring a late equaliser by producing an eye-catching reflex save from close range before substitute Jens Petter Hague scored the third for AC Milan in the fifth minute of injury time to seal the win for the visitors.
We've seen all of this before from Gianluigi Donnarumma, but the sight of the AC Milan custodian diving left, right and centre to make those stops remains one to behold. Oh, and how about his sweeper-keeper skills - Donnarumma racing out of his area to close down an onrushing Petagna and making a crucial block was something even Manuel Neuer would be proud of!
Flop: Hirving Lozano (Napoli)
After a difficult season last time, Hirving 'Chucky' Lozano was starting to show signs of life with Napoli this season, netting four times in Serie A before the AC Milan game, including an amazing double at Atalanta on matchday four.
Starting on the left side of a three-pronged attack behind the lone striker Mertens, this was another opportunity for the Mexican international to add to his tally, with Victor Osimhen absent from the scene.
However, Lozano contrived to have a stinker against AC Milan. Hernandez had his number for most of the opening stanza, with Lozano also blazing an effort from close range over the crossbar.
The 25-year-old ended the match with two key passes, the most by a Napoli player alongside Lorenzo Insigne and Matteo Politano, but failed to truly test Donnarumma before he was subbed off in the 56th minute.
Hit: Dries Mertens (Napoli)
It wasn't the most spectacular performance from Dries Mertens, but at least he broke his scoring duck to finally get back on the scoresheet for the Partenopei. Dries Mertens made Franck Kessie pay for his mistake by controlling the ball superbly before squirming a shot under Donnarumma.
That was only the third goal of the 2020-21 campaign, 127th overall, for Napoli's all-time top-scorer as he ended a goal-scoring drought of five games.
With Victor Osimhen absent from the Napolo lineup, the home side understandably had diminished attacking prowess, but Dries Mertens stepped up to the plate and gave his team hope of a comeback. However, that was not to be, as AC Milan scored their third at the death to beat Napoli at the San Paulo for the first time in almost a decade.