Neither team was able to convincingly get on top in a scrappy opening period at the San Siro. Christian Pulisic provided a rare moment of inspiration with a burst forward before being brought down by a cynical foul that earned Arthur Melo a yellow card, although it wasn’t long until moans could be heard from the crowd.
The lack of quality on display was then epitomised by Fiorentina’s Alfred Duncan, who made a complete mess of his effort from Fabiano Parisi’s cross.
Pulisic was once again the player to provide a moment of excitement in the 23rd minute with an instinctive strike, but that flew straight at Pietro Terracciano and was tipped over the crossbar.
Towards the end of a frustrating half, Tommaso Pobega forced Terracciano into the game’s first big save with a header that was tipped wide, and that moment seemed to bring the hosts to life.
Hernandez then raced through and was brought down by Parisi for a penalty that the Frenchman coolly converted himself to give the San Siro a lift.
There was immediate action at both ends in the second period, with Samuel Chukwueze seeing his header saved by Terracciano before Mike Maignan rushed out to steal the ball from Lucas Beltran.
A sloppy pass from Maignan went unpunished when Nicolas Gonzalez fired wide, but the Argentine gave the goalkeeper a scare with a cross that deflected off Fikayo Tomori and onto the post.
Fiorentina continued to push for an equaliser with Giacomo Bonaventura hitting a strike that was blocked from close quarters.
Luka Jovic then had a big chance to provide the hosts with some breathing space, only to see an unconvincing shot well saved by Terracciano before being replaced by Francesco Camarda - who became Serie A's youngest-ever debutant at 15 years, eight months and five days old.
Maignan then denied Rolando Mandragora’s shot from point-blank range with his face to ensure Milan ended a run of four consecutive league matches without a victory to reclaim third place in the table. Fiorentina, meanwhile, have lost four of their last five Serie A matches.
Flashscore Man of the Match: Theo Hernandez (AC Milan)
