After missing the chance to win the title at home against Salernitana, Napoli play away to Udinese on Thursday night.
The Neapolitans have an 18-point lead with just six matches to go.
To clinch the title mathematically, Napoli must not lose in Udine (assuming Lazio beat Sassuolo).
If Lazio fail to win tonight, Napoli will win the title before Thursday's match.
The match against Udinese will also be broadcast live at the Diego Armando Maradona stadium in Naples.
The 50,000 tickets, for fans who want to watch the match on the stadium's screens, sold out in just a few hours.
The tickets cost €5 and the entire amount raised will be donated to charity.
In addition to Napoli supporters at home, around 10,000 fans will also be supporting the team away at Udinese.