Napoli won their first major title since the Diego Maradona era, denied Serie A champions Juventus the double and handed their captain Alessandro Del Piero an unhappy end to 19 seasons at the club by beating the Turin side 2-0 in the Italian Cup final on Sunday.
Edinson Cavani broke the deadlock with a penalty just after the hour and Marek Hamsik finished off a counter-attack as Napoli claimed their first trophy since the Maradona-inspired team won Serie A in 1989/90.
Juventus had substitute Fabio Quagliarella sent off in the 89th minute for a full-blooded elbow in the face of Salvatore Aronica after only 17 minutes on the pitch.
"This was a club that didn't exist, said Napoli president Aurelio De Laurentiis, a film-maker who refounded the club after it was declared bankrupt in 2004 and led it from Serie C back to the top flight.
"In a few years we've brought something home, above all the knowledge that Napoli exists, lives and can be the world champion of the sport."
Napoli coach Walter Mazzarri said: "It seemed unthinkable to beat Juve.
"They hadn't ever lost this season (in Serie A) and to beat them 2-0 was magnificent work. The team has done something extraordinary in the last three years: Cavani, (Ezequiel) Lavezzi, Hamsik are on everyone's lips, but it's an entire team that should be acclaimed as one."
"This was the 51st game of the season. Anyone who plays football knows that playing these games at that level is hard. We have paid in the championship for this. You can lose to anyone in our league, and we dropped too many points."
Although Juventus had completed their 38-match campaign in Serie A without losing, there was some debate over their 2-2 Italian Cup draw after extra time against AC Milan in their semi-final second leg.
Milan claimed that, as they were winning 2-1 at the end of 90 minutes, that should count as a Juventus defeat.
Del Piero, 37, was told earlier this season that his contract at Juventus would not be renewed and the talismanic forward was given a standing ovation when he was substituted midway through the second half.
Juventus coach Antonio Conte kept to his regular cup line-up with Marco Storari in goal instead of Gianluigi Buffon and a starting role for Del Piero, who has been used mainly as a substitute in Serie A.
Napoli, who finished fifth in Serie A and missed out on the Champions League by three points.
Photograph: Paolo Bruno/Getty Images