Gonzalo Higuain struck in either half as Napoli toppled 10-man Inter Milan 2-1 in a spectacular clash at the San Paolo to go top of the Serie A table on Monday.

Inter travelled south for the first big away test of what they hope will be a title-winning campaign, but with just a two-point cushion on a Napoli side whose last defeat came on the opening day of the season.

Inter were shell-shocked by the lightning start of Maurizio Sarri's men and their hopes of staying top suffered a blow when Yuto Nagatomo saw red a minute before the interval.

But Inter regrouped and Adem Ljajic reduced arrears on the hour with a fine individual strike. Yet despite a battling finish that saw the visitors hit the woodwork twice, it wasn't enough to stop Napoli going a point clear at the top for the first time this season.

Inter drop to second with Fiorentina, held 1-1 at Sassuolo earlier Monday, a point further off the pace in third.

Roma's shock 2-0 home defeat to Atalanta has left embattled Rudi Garcia's side in fourth at four points behind Napoli, with champions Juventus now up to fifth, at seven points off the pace.

Napoli began at break-neck speed and a panicky Inter were made to pay for Jeison Murillo's mis-hit clearance on the edge of the area when it found its way to Higuain via a deft touch from Jose Callejon.

The Argentinian was left in space on the right and coolly volleyed past Samir Handanovic.

Napoli were giving Inter little time to settle and could have doubled their lead five minutes later when Marek Hamsik's cross found Callejon but the Spaniard's effort was skewed.

Inter were pegged back and it took Mancini's men until the quarter hour to settle, but after Ivan Perisic completely fluffed his effort Fredy Guarin drove a promising curling shot just over Pepe Reina's crossbar with the 'keeper rooted to the spot.

Napoli remained dangerous on the break but when Insigne powered down the left on 36 minutes to whip in a cross for Higuain, Nagatomo was on hand to cover as the ball flew wide.

Higuain was stopped again minutes later when, from just outside the area, his strike was charged down while at the other end Perisic spun his first-time effort wide from six yards out.

Nagatomo was given his marching orders, rather harshly, when he was cautioned for a second time after sliding in late but without malice to challenge Allan, who was left writhing on the ground.

Mancini introduced full-back Alex Telles for striker Mauro Icardi but Napoli soon added to their tally. Higuain was unstoppable as he out-sprinted Inter's centre-backs to smash his finish past Handanovic.

The Argentinian striker has now scored 12 goals this season two clear of Sampdoria striker Eder.

Inter reduced arrears minutes later when Ljajic fired low into the near bottom corner through a crowd of defenders.

Inter almost caused a sensation in added-on time when a Stevan Jovetic header bounced off the post. In the follow-up, Reina scrambled to tip Miranda's effort on to the other upright.

Earlier, title-chasing Fiorentina spurned the chance to go top after a 1-1 draw at feisty Sassuolo.

Borja Valero broke the deadlock after five minutes but Fiorentina were made to pay for a series of misses when Sergio Floccari headed home the leveller three minutes before the interval.