Milan: Lorenzo Insigne and Jose Callejon struck inside the opening minutes as classy Napoli kept their title hopes alive with a 2-1 win at AC Milan on Saturday.

A week after seeing Fiorentina stun leaders Juventus 2-1 to carve open the Serie A title race, AC Milan hoped to upset predictions at a packed San Siro.

But a year after Insigne’s double inspired the southerners to a famous 4-0 away romp, it took a superb second-half performance from Milan’s teenaged goalkeeper Gianluigi Donnarumma to limit the damage.

Napoli marksman Dries Mertens missed several chances to embellish the win, that saw Napoli remain third, reducing the gap on Juventus, who host Lazio on Sunday, to one point.

Roma are in second, also one point adrift before hosting Cagliari in Sunday’s late game.

“What I saw made me happy, although I would have been happier if we’d wrapped the match up earlier,” said Napoli coach Maurizio Sarri.

“We missed a couple of chances to go 3-0 up but I can’t point the finger too much at Mertens. He’s doing a great job for the team.”

Milan coach Vincenzo Montella drafted in Paraguayan Gustavo Gomez, 23, for suspended Alessandro Romagnoli at right-back but he struggled as Napoli hit two goals in the opening nine minutes.

Montella said: “There’s a little bit of bitterness at not snatching a draw but I’m satisfied.

“Napoli are doing very well, it’s not that my players are playing badly, and their goals were impressive. I’m disappointed with the result but I can’t fault my players.”

Mertens escaped down the right to collect Allan’s through ball before finding Insigne on the left flank.

The Italy midfielder took a touch before firing a superb drive that Donnarumma got his fingertips to before seeing it fly into the far top corner.

Insigne’s sixth goal of the campaign should have prompted a quick reaction, but Milan seemed to do the opposite.

Mertens, on 12 league goals since stepping in to replace injured Polish striker Arkaduisz Milik, earned his second assist of the game all too easily minutes later.

After coolly sidestepping Gomez, the Belgian’s ball in behind the Milan defence found an overlapping Callejon, who raced in to beat the onrushing Donnarumma down low from a nearly impossible angle.

Kucka then pounced on a loose ball following a moment of confusion between Jorginho and Tonelli to poke the ball past the onrushing Pepe Reina eight minutes before the interval.