In what was a gripping encounter in southern Italy, the hosts failed to find the breakthrough despite their dominance, as Edy Reja will be delighted to leave Naples with a point
Despite the late drama, the first-half was rather forgettable, with just Hugo Campagnaro's wayward header from Ezequiel Lavezzi's acutely clipped-in free-kick being the only chance of note, while the visitors could only muster a Hernanes shot from distance.
However, the match exploded into life after the interval, as goalkeeper Federico Marchetti eventually stole the show via a number of top-drawer saves to frustrate Napoli, who began to step up the tempo.
Lavezzi was at the forefront of the opportunites presented to the former Cagliari No.1, with a curling effort from range requiring him to be on his toes and dive the ball away. An acrobatic attempt also surfaced from Edinson Cavani's flick-on, but it proved to be futile once more.
Blerim Dzemaili also got into the habit of examining Marchetti's nerve with a vicious free-kick from 25 yards out, but his effort whistled just wide of the target.
An inefficient Lazio continued to go through the motions, as Djibril Cisse struggled to lead the line on the night without the assistance of top-scorer Miroslav Klose, and they could only back down to Napoli's dominance.
Mazzarri threw on Goran Pandev in a last-ditch attempt to swing the game into the hosts favour, but Marchetti again stood firm and superbly managed to stop Lavezzi during the last kick of the game in the 94th minute, as Lazio now temporarily move top of Serie A.