Zlatan Ibrahimovic struck twice in his first match back from coronavirus on Saturday as AC Milan beat city rivals Inter Milan 2-1 to take top spot in Serie A ahead of Atalanta who slumped 4-1 at Napoli.

Ibrahimovic had not played since September 21, but bagged his second brace in as many league matches this season as Milan claimed their first derby win since January 2016.

Milan have now won their opening four Serie A matches for the first time since the 1995-1996 season when they won the title under Fabio Capello.

The 39-year-old Ibrahimovic stamped his mark on the game early, having also scored back in February only for Inter to win 4-2.

He missed a penalty after 13 minutes but turned in the rebound, with a perfect Rafael Leao cross setting up the Swede for the second three minutes later.

"Ibra was very tired and asked me to come off, but I didn't let him. He was too important to us," said Milan coach Stefano Pioli.

"Zlatan is a champion, an exemplary professional, who always wants to win, everything.

"We continue to work and grow but the road is still long."

Romelu Lukaku pulled a goal back for Inter Milan after half an hour for his fourth goal in as many matches but Antonio Conte's side were struggling with six players out to Covid-19.

A Lautaro Martinez header was cleared off the line and Lukaku sent a header wide before the break. He was also denied by Gianluigi Donnarumma before the final whistle.

AC Milan are top of the table with maximum 12 points, three ahead of Atalanta who fell to third-placed Napoli.

Inter Milan are sixth with seven points from three games.

In Naples, Hirving Lozano struck twice as Napoli powered back days after they were deducted a point for failing to turn up for their last Serie A game against Juventus.

But Gennaro Gattuso's side picked up where they left off before the coronavirus row, with a third win in as many league games they have played.

"I've heard say that we didn't want to go (to Turin), it's not true," said Gattuso.

"I'm more angry than anyone that we weren't allowed to go."

Napoli maintained they had to remain in isolation on local health authority instructions.

"Juventus are a team under construction," continued Gattuso. "I had the feeling that we could play that match like we did today."

Slovenian forward Josip Ilicic returned for highly-fancied Atalanta after nearly three months out with personal problems, starting up front alongside Papu Gomez and Duvan Zapata.

But Mexican forward Lozano scored two quick-fire goals in the first half, his second so far this season.

But with many players returning from international duty Gian Piero Gasperini's side lacked the fire power of their previous three games in which they had scored 13 goals.

Lozano tapped in a Giovanni Di Lorenzo cross after 20 minutes, curling in the second minutes later after a mix-up in the Atalanta defence.

Matteo Politano blasted in a third after half an hour with Victor Osimhen scoring his first Napoli goal just before the break after another defensive blunder.

Osimhen held up a t-shirt after his debut goal on which was written "End Police Brutality in Nigeria" as protests against law enforcement violence continue in his home country.

Substitute Sam Lammers pulled a goal back with 20 minutes to go, but Atalanta drop into second place with Napoli a point behind them in third.

"This defeat as a wake-up call," said Gasperini ahead of their Champions League opener against Danish club Midtjylland.

"We had problems from every point of view, we suffered against Napoli."

Lazio, without suspended striker Ciro Immobile, fell to a 3-0 defat at Sampdoria, before their Champions League opener against Borussia Dortmund.