The 39-year-old netted a trademark bullet header and a close-range volley either side of halftime to bring his impressive tally up to 10 goals in six league games this season.
However, there was a sour end to AC Milan’s night as Ibrahimovic left the pitch early after suffering a leg injury.
“I don’t have much information, he had ice on his thigh and we’ll see in the next few days what the tests say,” AC Milan’s assistant coach Daniele Bonera told Sky Sports after the game.
The Swedish striker has been monumental for his side this season and has been central to its current unbeaten league run which extends back to March.
“I’m like Benjamin Button, I’ve always been young, never old,” he told Milan TV.
Dries Mertens had initially pulled one back for Napoli but Jens Petter Hauge put the game to bed in stoppage time to secure Milan’s first win in this fixture after 11 attempts.
Ibrahimovic scored the last time Milan beat Napoli away in 2010, during his first spell at the club.
The Rossoneri remains two points clear of Sassuolo at the top of the table but Bonera, who had replaced Stefano Pioli after the head coach had tested positive for Covid-19, refused to call his side contenders.
“We want to stay high up the table but after eight rounds it’s too soon to get carried away,” he added.
“There are teams that have invested more than us and that were built to win the league. We weren’t built to win straight away, but we’re growing game after game.”
La Liga surprise
European soccer has been unpredictable at best this season as it returns from lockdown and there continues to be a surprising leader atop the La Liga table.
Real Sociedad earned its sixth consecutive league victory on Sunday after battling past a resilient Cadiz side still looking for its first home win in La Liga this season.
A goal from Alexander Isak was all that was needed to take all three points as Sociedad remained at the summit of Spanish football, three points clear of Atletico Madrid having played two games more.
Barcelona, which lost 1-0 to Atletico on Saturday is down in 12th place whilst Real Madrid sits in fourth after its 1-1 draw with Villarreal.