Matias Olivera looked to have put the hosts on track to clinch the third league title in their history when he headed them ahead on 71 minutes.
But Boulaye Dia equalised for the visitors shortly after with a fine curling shot to deny Napoli a victory that would have delivered their first Serie A crown since 1990, when late football great Diego Maradona graced the team.
The celebrations have only been delayed as there is no realistic chance of Napoli being overtaken, given their huge lead at the top of the table.
Luciano Spalletti’s side sit on top with 79 points and six games to go, while second-placed Lazio have 61 after losing 3-1 at Inter earlier on Sunday.
This means that Lazio can only finish on a maximum of 79 points.
Napoli need just one draw from their remaining six games, or they would need Lazio to drop points in just one.
Juventus can leapfrog Lazio and take their tally up to 62 points if they win at Bologna later on Sunday.
Spalletti was philosophical about Sunday's outcome “Obviously, the lads are very sorry not to have given this joy to the fans,” he told DAZN.
“We came up against a motivated team that shut up shop and we were a bit naive with the goal we conceded.
“We want to see people celebrate. We represent their dreams.
“Let's just postpone the party and this prolongs the joy and the celebrations.
“I am convinced we will get that point (we still need to win the championship).”
ANSA
