Inter put an end to Napoli's 100 per cent record in Serie A this season as Italy's top two fought out a fascinating but ultimately frustrating 0-0 draw at Stadio San Paolo on Saturday.
Looking to get back to winning ways following Tuesday's 2-1 Champions League loss to Manchester City, league leaders Napoli were denied a ninth straight league victory by the brilliance of visiting goalkeeper Samir Handanovic.
The Slovenian produced a sparkling double save in the first half of a tense battle and denied Dries Mertens in injury time as the hosts failed to find the net for the first time since a 2-0 loss to Atalanta in February.
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While Napoli failed to make it nine wins on the spin, the result at least maintains their two-point lead over nearest rivals Inter at the summit.
However, the draw also allows reigning champions Juventus - who travel to Udinese on Sunday - the chance to close the gap on the top two in what is shaping up to be an enthralling early title race.
Having sat out the midweek loss in Europe, midfield duo Jorginho and Allan both returned to Napoli's starting XI. There was also the unexpected inclusion of Lorenzo Insigne, who had hobbled off in the second half at the Etihad Stadium with a right adductor strain.
Inter, meanwhile, had enjoyed a satisfying break after their exertions in the Derby della Madonnina last Sunday, allowing Luciano Spalletti to pick an unchanged side.
The visitors were indebted to Handanovic for coming through a lively first half unscathed, as the goalkeeper denied Napoli twice in quick succession in the 20th minute.
Having initially dived low to his left to keep out a first-time drive from Jose Callejon, Handanovic reacted quickly while still grounded to flip his body to the right and block Mertens' attempt to convert the rebound.
Mauro Icardi and Borja Valero did force Pepe Reina into action as Inter grew as an attacking threat, yet they were fortunate Insigne failed to convert a free header from Marek Hamsik's lofted pass to the back post.
A break from deep by Matias Vecino breached Napoli's high defensive line early in the second half but although he rounded Reina, his chip from a tight angle was drifting wide before the retreating Elseid Hysaj headed clear.
Captain Hamsik failed to take an opportunity to draw level with Diego Maradona on 115 goals for Napoli from Callejon's clever knockdown, dragging his attempt wide to the left from the edge of the area.
But, as has become common in games this season, the hosts faded as an attacking force once the influential Hamsik - a driving force in their engine room - was withdrawn in the 71st minute.
After replacement Piotr Zielinski tested his reactions with a stinging volley from distance, Handanovic denied Mertens again with a point-blank save as the game slipped into stoppage time.
While still without a win at the ground since 1997, Inter at least held firm to pick up a point and deny Maurizio Sarri's usually free-scoring side from stretching their lead in the standings.