A first-half winner from Luca Toni secured a precious 1-0 win for Fiorentina over Palermo and relegated the Sicilians from Italy's Serie A on Sunday.
Fiorentina's 20th win of the campaign kept them in fourth but boosted their push for a third-place finish which offers Champions League football next season via a preliminary round.
Vincenzo Montella's side are now only one point behind third-placed AC Milan, who will look to restore their four-point cushion at home to Roma in Sunday's late match.
Montella's leadership this season has prompted talk of a move to richer pastures but he indicated that he would happily stay with the club.
"We are discussing the length of the contract. The most important thing is we remain together but also that we know exactly what our plans are," said the 38-year-old.
Palermo, meanwhile, join already-relegated Pescara in Serie B having failed to close the gap to Genoa.
It means the Rosanero return to Serie B for the first time since their triumphant 2003-2004 season in Italy's second tier.
Coach Giuseppe Sannino, sacked from his post by Palermo president Maurizio Zamparini in September only to be re-hired in March after Gian Piero Gasperini suffered the same fate, said he was unsure of his future.
"It's not the right time to decide my future at the club, you can't make decisions with your heart. We have to sit down to discuss many issues," said Sannino.
"Everyone needs to accept their part of responsiblity for this. I am not a miracle worker."
He added: "We need people who are not afraid to suffer and who love this shirt."
Joining Palermo and Pescara in Serie B are Siena, whose relegation was decided by games elsewhere on Sunday even before their trip to Napoli.
Genoa began the day with a four-point cushion over Palermo but are now five points ahead having played out a scoreless draw at home to Inter Milan.
Inter were the last Italian club to win the Champions League, in 2010, but having started this league campaign positively the Nerazzurri are set for a finish just above mid-table and will not play in Europe next season.
Andrea Stramaccioni's side have been decimated by injuries in recent months and this latest setback will heap further pressure on the 37-year-old coach.
Stramaccioni, however, claims to have the backing of Inter president Massimo Moratti as he looks ahead to an improved campaign in 2014.
"We have a strong relationship which is honest and sincere," said Stramaccioni.
"I'm optimistic and convinced that we can lay the foundations for a better campaign next season."
Elsewhere Alessio Cerci's 19th-minute equaliser for Torino rescued a share of the spoils on their trip to Chievo.
Chievo opened the scoring through Frenchman Cyril Thereau on 10 minutes but Cerci levelled from the penalty spot barely 10 minutes later.
Later Sunday Lazio host Sampdoria hoping for a win that would boost their chances of a top-five finish and a place in next season's Europa League.
Napoli are already assured of the runner's up spot and host Siena at the San Paolo stadium, Udinese host Atalanta and Bologna are away to Parma in a match which has little to offer either side.
Roma, also still in the Europa League hunt, travel to AC Milan in Sunday's late match where defeat for the hosts would be a huge boost for Fiorentina ahead of next weekend's final game of the season.
Juventus celebrated their 29th league title on Saturday following a 1-1 draw at home to Cagliari which means the Bianconeri, on 87 points, can not now beat the record 91-point tally set by Fabio Capello in 2006 when he was coach of the Serie A giants.