ROME (AP) — Napoli is halfway to its first Serie A title since Diego Maradona led the club to the 1990 championship.
Gonzalo Higuain scored twice as Napoli routed promoted Frosinone 5-1 Sunday to earn the southern team the Italian league's symbolic "winter title."
Through 19 rounds of the 38-match season, Napoli holds a two-point lead over four-time defending champion Juventus and Inter Milan.
Paul Pogba and Sami Khedira scored as Juventus won 2-1 at Sampdoria for its ninth consecutive victory, while Inter was beaten 1-0 by Sassuolo with a last-minute penalty to surrender the lead.
The winter champion has gone on to win Serie A nearly seven out of every 10 seasons.
"We're still not sure what we're capable of," Napoli's first-year manager Maurizio Sarri said. "But this was a big step forward."
The last time Napoli earned the mid-term honor came in 1990.
"Being winter champion means nothing. It means something when you're champion in May," Higuain said. "We've got to stay calm now because there are still five months to go and we want to continue this way."
Raul Albiol put Napoli ahead from close range midway through the first half when Frosinone goalkeeper Massimo Zappino appeared blinded by the sun.
Higuain added a penalty on the half-hour mark, Marek Hamsik then scored his third goal in three matches with an impressive solo move after the break, before Higuain dribbled past three defenders to score his league-best 18th.
Substitute Manolo Gabbiadini added another for Napoli with a shot from beyond the area and Paolo Sammarco then pulled one back for Frosinone, a club located midway between Rome and Naples.
The toughest challenge for Napoli might be maintaining its focus amid fan delirium in football-crazy Naples. Already, Napoli fans started celebrating wildly when the team beat Inter to take the lead in November, only to be let down by a 3-2 loss to Bologna a week later.
"It's true that the enthusiasm of Neapolitans approaches euphoria, but we shouldn't fear the (attention)," Sarri said. "We have to grow in terms of our mentality and handling certain matches, like the Bologna game."
Next weekend, Napoli hosts Sassuolo.
Fiorentina is fourth, three points behind, after losing 3-1 to Lazio on Saturday.
Also Sunday, it was: Atalanta 0, Genoa 2; Bologna 0, Chievo Verona 1; Torino 0, Empoli 1; and Hellas Verona 0, Palermo 1.
In Genoa, Pogba put Juventus ahead with an expert chest control and low shot inside the area and Khedira doubled the lead after the break with a similar goal. A rejuvenated Antonio Cassano pulled one back for Samp in the 64th by shooting between two defenders.
Earlier, Domenico Berardi converted the decisive spot kick for Sassuolo five minutes into added time after Inter defender Joao Miranda was shown a yellow card for a foul on Gregoire Defrel.
In an entertaining match at the San Siro, both Inter and Sassuolo produced numerous chances and goalkeepers Samir Handanovic and Andrea Consigli were superb.
Inter threatened early with Mauro Icardi and Adem Ljajic, then Simone Missiroli and Nicola Sansone were dangerous for Sassuolo.
Handanovic tipped a free kick from Sansone over the bar and Consigli made an extraordinary diving save to swat away a shot from Ljajic before the break.
Inter substitute Rodrigo Palacio had a clear look in the 79th but his effort was cleared off the line by defender Federico Peluso.
Miranda's decisive foul came after an error by fellow center back Jeison Murillo.
Berardi then calmly beat Handanovic, improving to a perfect 6-for-6 on penalties this season.
Having been beaten by Lazio before the holiday break, Inter has now lost two consecutive home matches in Serie A for the first time since May 2013.
Sassuolo is sixth, 10 points behind Napoli.