Champions Juventus returned to the top of Serie A with a 4-0 home rout of Cagliari on Wednesday, while former leaders Napoli dropped to second after being held to a goalless draw at Genoa.

First-half efforts from Daniele Rugani, Gonzalo Higuain and Dani Alves and a late own goal from Luca Ceppitelli helped Juve ease to their fourth win of the season and up to 12 points, one ahead of Napoli on 11.

Inter Milan beat Empoli 2-0 away after a first-half double from Mauro Icardi to go fifth on 10 points, while Roma jumped to third, also on 10, after thrashing Crotone 4-0.

Juve boss Massimiliano Allegri made six changes after they lost to Inter on Sunday, with record signing Gonzalo Higuain restored to the starting lineup.

However, it was defender Rugani who opened the scoring with a poacher's finish, reacting first to tap past Marco Storari after the keeper saved from Higuain's volley.

Higuain did get on the scoresheet in the 34th minute when he fired home the rebound after Storari had blocked Miralem Pjanic's effort.

Dani Alves added a third six minutes later with his first for Juve, lashing the ball into the bottom corner from the edge of the box after being picked out by a Pjanic corner.

Juve replaced goalkeeper Gianluigi Buffon at halftime due to injury, but added to their tally in the 83rd minute when Ceppitelli deflected the ball past Storari.

Napoli, Serie A's top scorers heading into Wednesday, were held at Genoa despite enjoying the lion's share of possession.

Marek Hamsik struck the woodwork as Maurizio Sarri's side were forced to settle for a point.

Inter took the lead against Empoli after 10 minutes when Icardi met Antonio Candreva's delightful chipped cross with a diving header.

They doubled their advantage seven minutes later when Icardi was picked out by Mario and slotted calmly past Lukasz Skorupski for his sixth goal of the season.

At the Stadio Olimpico, Roma eased past promoted Crotone in a 4-0 triumph that hinted that Luciano Spalletti's side could be title contenders again.

Stephan El Shaarawy struck in the 26th minute after a sustained period of pressure from the home side, while Mohamed Salah added a second with a thunderous left-footed finish from close range 11 minutes later.

Edin Dzeko bagged two in the second half, the first after a remarkable assist from Francesco Totti, while Wojciech Szczesny saved Raffaele Palladino's penalty.