Napoli moved third in Serie A on Sunday after strolling to a 4-0 win over bottom side Crotone, taking advantage of rivals Roma and Sassuolo battling to an entertaining goalless draw.

Gennaro Gattuso's side are on 20 points, level with Juventus and three behind leaders AC Milan after goals from Lorenzo Insigne, Hirving Lozano, Diego Demme and Andrea Petagna earned the away side a simple three points despite starting without Dries Mertens and the injured Victor Osimhen.

Milan can go five points ahead of second-placed local rivals Inter Milan when they travel to Sampdoria later on Sunday.

Insigne opened the scoring with a trademark curling strike after cutting in from the left with half an hour gone, and the task became simpler for the away side five minutes after the break when Jacopo Petriccione was sent off for a late, high challenge on Demme.

Italy international Insigne then laid on Lozano for the second with a superb long pass that left the Mexican with a simple finish, and Demme made sure of the result with a drilled low strike 14 minutes from the end following a lay-off from substitute Mertens.

Belgium forward Mertens then supplied the pass that allowed Petagna to hammer home the fourth in stoppage time as Napoli temporarily closed the gap between them and Milan.

Roma meanwhile were left ruing missed chances after their home draw with Sassuolo as both teams had goals ruled out by VAR and the hosts played the second half with 10 men.

Roma are five points off the lead in sixth after wasting opportunities to win despite having a man less for 50 minutes, while Sassuolo are a one ahead in fifth.

Pedro was sent off for a second bookable offence five minutes before the break. His coach Paulo Fonseca followed him to the stands at the end of the first half after Henrikh Mkhitaryan's goal was ruled out for a foul by Edin Dzeko following a VAR check.

The hosts dominated after the break despite being outnumbered and were unlucky to not take the lead when Leonardo Spinazzola's cross was guided onto the post by Sassuolo defender Gian Marco Ferrari, under pressure from Dzeko.

Sassuolo thought they had snatched the points with 15 minutes left when Lukas Haraslin whipped a long-range shot past Antonio Mirante, only for the goal to be ruled out for the tightest of offsides by VAR.

"I'm very proud of my team. We played very well even when down to 10. We were very well organised defensively and didn't allow Sassuolo many opportunities," Fonseca told Sky Italia.

Parma's match with newly-promoted Benevento also finished goalless while mid-table side Hellas Verona drew 1-1 with Cagliari.

Atalanta's match at Udinese was postponed after heavy rain made the pitch unplayable.