Napoli will have to wait for their first Serie A title in 33 years after they were held to a draw by Salernitana at the Stadio Diego Armando Maradona.
They last won the league in 1990 with a Diego Maradona-inspired side adding to the club’s first title in 1987.
Luciano Spalletti’s side were on course for the victory they needed when Mathias Olivera headed home a 62nd-minute corner.
But Boulaye Dia equalised with a left-footed drive six minutes from time.
It silenced an expectant crowd who made a cacophony of noise and set off blue smoke flares inside and outside the stadium, where thousands of fans lined the streets, when Napoli went ahead.
Despite the disappointment Spalletti’s side are almost certain to win the title, with just two points needed from their final six games.
It will mark a first league title success without talisman Maradona, with Napoli only having won five Italian Cups in 89 years without the Argentina forward at the club.
Their next chance to secure the title will come when they travel to Udinese on Thursday (19:45 BST), but they could also win it before then if results go their way.
Second-placed Lazio, who are 18 points behind, must beat Sassuolo on Wednesday (20:00 BST), while Juventus, who are 20 points behind in third with a game in hand, must win later on Sunday (19:45 BST) and on Wednesday.
Napoli were given the chance to wrap up the title with a record-breaking six games to go after Lazio were beaten 3-1 at Inter Milan earlier on Sunday.
Argentina forward Lautaro MartÃnez came off the bench to score twice and help Inter recover from a 1-0 deficit.