Sampdoria were relegated to Serie B after losing their penultimate match of the season 2-1 at home to Palermo. The defeat saw them drift five points away from safety with a game to go.
Fabrizio Miccoli put Palermo ahead in first-half stoppage-time before Jonathan Biabiany brought Sampdoria back into the match early in the second half.
But as they committed men forward, they conceded a second goal to Mauricio Pinilla. That result, combined with Lecce's victory, condemned Samp to the drop.
Sampdoria's relegation caps an astonishing decline; just 12 months ago they were celebrating qualification for the Champions League play-offs, though defeat to Werder Bremen meant they missed out on qualifying for the competition proper.
The January sales of Giampaolo Pazzini and Antonio Cassano - their two star players - badly harmed their chances of survival and the Genoans have only won three games since December 5.
Inter Milan guaranteed themselves second place while Napoli settled for third and automatic qualification for the Champions League as the two sides played out a 1-1 draw.
Samuel Eto'o put Inter ahead in the 14th minute before Camilo Zuniga levelled for Napoli on the stroke of half-time.
Jeda was the difference as Luigi De Canio's Lecce completed their great escape with a 2-0 win over already-doomed local rivals Bari, confirming Serie A survival for another season.
The Brazilian opened the scoring in the 52nd minute and then saw his 80th-minute shot - which was going off target - turned into his net by Bari's Andrea Masiello.
At the other end, Udinese moved back into fourth place - the final Champions League qualification spot - with a 2-0 victory at Chievo.
Mauricio Isla put the visitors ahead from long range before the half-hour mark and Kwadwo Asamoah doubled their advantage with 15 minutes remaining.
The Friuli outfit held on to claim three vital points at Verona's Stadio Bentegodi to go two points clear of fifth-placed Lazio - who beat Genoa 4-2 yesterday - heading into the final week of the season.
Bologna all but mathematically secured their place in Serie A next season with a 1-1 draw at local rivals Fiorentina. Alessio Cerci put the home team in front in the 20th minute, but Bologna hit back with a strong second half which should have seen them take all three points.
Gaston Ramirez brought them level in the 50th minute before Marco Di Vaio missed a penalty as Per Kroldrup was sent off. The visitors should have had another penalty late on, but a mistake by the referee saw Bologna striker Gaston Ramirez instead shown the red card as both sides ended the match with 10 men, and a point each.
Cesena preserved their top-flight status, with a 1-0 victory over already-relegated Brescia at Stadio Dino Manuzzi continuing their fine finish to the Serie A season. The Cavallucci Marini were all but certain of their Serie A status for another year after just one defeat in their previous six games - but Emanuele Giaccherini's goal just before the hour guaranteed safety.
Roma's Champions League hopes are over after they lost 2-1 at Catania. Simone Loria put the Giallorossi ahead but Gonzalo Bergessio levelled before Alejandro Gomez grabbed the winner deep into stoppage time.
Juventus failed to take advantage of Roma's defeat as a 1-0 reverse at Parma saw them remain just outside the Europa League places.
The Bianconeri needed to win at Stadio Ennio Tardini and hope that Roma did not pick up any points if they were to move into the Serie A top six with one round of games to go.
Catania's 2-1 win gave Luigi Del Neri's men the chance to leapfrog their rivals but ex-Juve midfielder Sebastian Giovinco struck the only goal of the game for mid-table Parma.