Napoli coach Maurizio Sarri might be keen to play down his team's chances of winning the league title but it is now the only side with a perfect record in Serie A after six-time defending champion Juventus drew 2-2 at Atalanta on Sunday.
Napoli beat Cagliari 3-0 and moved into the sole lead of Serie A, two points ahead of Juventus and Inter Milan, which won 2-1 at last-place Benevento.
Juventus let slip a two-goal lead, while Paulo Dybala also had a late penalty saved.
"Juve, together with Napoli, Roma and Inter will fight for the title right until the end," Juventus coach Massimiliano Allegri said. "Nothing changes for us, the season is long, today we dropped two points but we have to remain calm because I feared we could even lose ... so this draw will be useful for the standings."
Atalanta hadn't beaten Juventus in more than 16 years and that run looked set to continue when Juventus scored two goals in three first-half minutes.
Blaise Matuidi's effort was parried by Etrit Berisha but Federico Bernardeschi netted the rebound.
The young Italy forward then turned provider with a through-ball for Gonzalo Higuain, who held off leonardo Spinazzola and thumped it into the net.
Atalanta got back into the match in the 31st as Gianluigi Buffon couldn't hold Papu Gomez's free kick and Mattia Caldara — who is owned by Juventus — turned in the rebound.
Mario Mandzukic thought he had extended Juve's lead in the second half but his headed goal was ruled out on video review for a foul by Stephan lichtsteiner.
And Atalanta leveled 10 minutes later when Bryan Cristante headed Gomez's cross into the top left corner.
Juventus had a chance to restore its lead when it was awarded a penalty on video review after Dybala's free kick hit Andrea Petagna on the shoulder. But Berisha saved the Argentina forward's spot kick.
TARGET PRACTICE
It was more target practice for Napoli, which has now outscored the opposition 25-5 by producing at least three goals in each of the team's Italian league games this season. Having finished in the top three spots in five of the last seven seasons, Napoli is looking more and more like it could win its first title since Diego Maradona led the club to its only two Serie A championships in 1987 and 1990.
"It's been six years that people have been saying we could bother Juventus but in the end they still win, which means that they're still a step above everyone else," Sarri said.
Marek Hamsik scored his first goal of the season four minutes in at the San Paolo stadium with a low, angled shot after trading passes with Dries Mertens.
It was Hamsik's 114th goal in all competitions for Napoli, moving him within one of Maradona's club record.
Mertens earned a penalty and converted the spot kick to double the advantage before the break and Kalidou Koulibaly added another two minutes into the second half.