Venezia started with real intent, but it was Giacomo Raspadori who nearly stunned the home faithful with a thunderous left-footed strike that rattled the inside of the left post before bouncing back into play.
Moments later, Scott McTominay tested Ionut Radu with two powerful headers from set-piece deliveries, forcing the Venezia shot-stopper into a pair of superb saves as Napoli pressed forward in a bid to keep pace with league leaders Inter Milan.
However, the Lagunari had their best chances at the other end just before the break, when Kike Perez latched onto a cross inside the box and directed a low effort towards the bottom-right corner, only for Alex Meret to make a comfortable stop.
Seconds later, Amir Rrahmani was on hand to clear Daniel Fila’s shot off the goal line after a chaotic rebound inside the penalty area.
Despite the pressure, Napoli nearly took the lead at the very end via Romelu Lukaku’s header, which Radu masterfully saved on the goal line to end an exciting first period.
Antonio Conte’s men upped the tempo after the break, asserting control over the game but failing to find the cutting edge in the final third.
Venezia’s ongoing 11-game winless run began with a narrow 1-0 loss to Napoli in December’s reverse fixture, and as the match wore on, the hosts appeared increasingly vulnerable to conceding first.
However, Eusebio Di Francesco’s decision to introduce two pairs of fresh legs with 20 minutes to go injected new energy into Venezia’s attack, unsettling Napoli’s defence and shifting the momentum.
In the end, neither side found an elusive winner, playing out a first draw since December 2003 in Serie B.
Napoli suffer another blow in their pursuit of reclaiming the Scudetto, giving both Atalanta and Inter Milan the upper hand following a seventh draw this season.
Venezia, meanwhile, still linger five points adrift of safety, with their return to the Italian second tier looking increasingly likely as the rounds go by.
Flashscore Man of the Match: Ionut Radu (Venezia)