Napoli won their first Serie A title for 33 years as they drew with Udinese at Dacia Arena to spark jubilant celebrations back in Naples.
They last won the league in 1990 with a Diego Maradona-inspired side adding to their first title three years earlier.
Victor Osimhen smashed in a 52nd-minute equaliser after Sandi Lovric had given Udinese a shock lead.
And Napoli held on to the point they needed to win their third Serie A title with five games to spare.
“Seeing Neapolitans happy is enough to give you a sense of that joy they are feeling,” Napoli boss Luciano Spalletti told DAZN.
“These people will look to this moment when life gets hard, they have every right to celebrate like this.
“You feel a bit more relaxed knowing that you’ve given them this moment of happiness.”
Napoli’s previous two titles came in the days of Argentina legend Maradona – who their stadium is now named after – in 1987 and 1990.
Following those glory days the club fell into financial decline, relegation and bankruptcy; playing in Serie C as recently as 2006.
They have won the Coppa Italia three times in the past 11 seasons but it is the Scudetto the Napoli fans craved.
They now have a new cast of superstars, with Nigeria forward Victor Osimhen scoring 21 goals in 26 league games and Georgia winger Khvicha Kvaratskhelia contributing 12 goals and 10 assists.
At 64 boss Luciano Spalletti, who twice won the Coppa Italia with Roma, becomes the oldest manager to win Serie A.
His team had the chance to lift the title with six games to spare last weekend but could only draw with local rivals Salernitana.
But with a 16-point advantage over second-placed Lazio their third Serie A title is now confirmed.