Gonzalo Higuain hit his 22nd goal in as many Serie A games to keep his record-chasing quest intact on Sunday as Napoli reclaimed top spot with a 5-1 drubbing of Empoli.

Champions Juventus had earlier gone top with a 4-0 rout of Chievo in Verona where Alvaro Morata hit a brace to take his goals tally to four this week after netting twice in a 3-0 Cup semi-final win over Inter Milan.

But Napoli, bidding for their first league crown since Diego Maradona's heyday at the club in 1990, restored their two-point advantage to further underline their 'scudetto' credentials.

Napoli now sit top on 50 points, two ahead of Juventus and eight in front of Fiorentina after La Viola failed to break down Genoa in a scoreless stalemate at the Luigi Ferraris.

Regarded only weeks ago as the tighest 'scudetto' race in decades, Inter Milan's 3-0 defeat to AC Milan in the city derby means it is steadily becoming a two-horse race between Napoli and four-time consecutive champions Juve.

Inter remain fourth, but are nine points adrift and only three ahead of Roma, meaning the big winners were Napoli, Juventus and AC Milan.

Napoli coach Maurizio Sarri, however, said: "We're playing well and we're in good condition, but I'm not certain we can keep this up all the way till the end of the season."

As Napoli target a first title in 26 years, Higuain is chasing Serie A's all-time record of 35 goals scored in a single, 20-team league season, set by AC Milan forward Gunnar Nordahl in 1950.

With 16 games remaining, the Argentinian international is not slowing down although he was replaced halfway during the second half when he received treatment after landing heavily from a mid-air clash.

After Empoli 'keeper Lukasz Skorupski parried an early chance from Higuain, the San Paolo was stunned into silence when Leandro Paredes's free kick deflected andleft Reina wrong-footed in the Napoli net on the half hour.

But the goal served only to spur Napoli into life and when Insigne burst down the left minutes later, the diminutive playmaker had time to pick out Higuain, who nodded past Skorupski from close range.

Napoli won a free kick four minutes later and Insigne stepped up to curl the ball past Skorupski to give the hosts a 37th minute lead, taking his own personal tally in the league to 10.

Napoli were unstoppable after the interval, Jose Callejon playing a role in all three goals on his way to a personal double.

Seven minutes after the restart Michele Camporese deflected Callejon's delivery past Skorupski at the keeper's near post.

The two-goal cushion was enough for Sarri, who spent two years at Empoli prior to succeeding Rafael Benitez at Napoli, to replace Higuain with Manolo Gabbiadini 20 minutes from the end, with Dries Mertens replacing Insigne three minutes later.

Mertens soon turned provider with a great curling delivery that Callejon poked into the net seven minutes from time.

With two minutes on the clock, Callejon doubled his tally with an angled strike that sneaked inside the near post.

Earlier, Juventus coach Massimiliano Allegri was quick to play down his side's title hopes despite equalling a club record of 12 consecutive wins.

"There are still 16 games left and lots of points to play for so it's far from over," Allegri told Sky Sport.

"It's the players who go out there and play, they win the games and I'm only there to lend a hand.

"To me, records don't matter. What's the point of winning 20 in a row if it doesn't win you the title."

Roberto Mancini gave new Inter recruit Eder his debut in what must have been a baptism of fire at the San Siro.

But despite a bright start, Inter were 1-0 down on 35 minutes when Alex headed in at the back post.

After second-half substitute Mauro Icardi missed a penalty on 70 minutes, Carlos Bacca and M'Baye Niang pushed the dagger in further with a goal apiece in the closing quarter hour.