A double strike from John Utaka amid crazy scenes in Auxerre was enough to seal the French title for Montpellier as they picked up a deserved 2-1 win.
Montpellier began the day three points clear of PSG at the summit, but they were made to sweat before securing the title as trouble in the stands twice forced the suspension of their match at Auxerre.
After Utaka's first goal of the night had cancelled out Olivier Kapo's 20th-minute opener for the hosts, the action was first halted early in the second half after some home fans expressed their annoyance at their recent relegation by littering the pitch with tennis balls, tomatoes and toilet paper.
Order was quickly restored, but around 20 minutes from full-time the action was halted again for several minutes after fans reportedly released smoke bombs.
When play was finally able to get under way once again, Montpellier took the lead for good in the 76th minute when Utaka turned in the area and fired home to spark scenes of jubilation among the travelling faithful.
Second-placed PSG had earlier seen their match at Lorient suspended for four minutes during the first half after some of their fans threw smoke bombs, forcing the players from the pitch while the smoke cleared.
At the time of the stoppage PSG were trailing 1-0 to a Kevin Monnet-Paquet strike after 28 minutes, but the capital club made sure of the 2-1 win with second-half goals by Javier Pastore and Thiago Motto. But it was not enough.
Eden Hazard signed off his Lille career with a stunning hat-trick as Rudi Garcia's side completed their campaign with a comfortable 4-1 victory over mid-table Nancy.
Hazard - almost certain to move to the Premier League in the summer - scored all his goals in the first half as Lille coasted home, having already secured third place and a Champions League berth for next season.
At the other end of the table, Ajaccio pulled off the great escape with a battling 2-0 victory at Toulouse. Olivier Pantaloni's men began the day third from bottom in the table and needing three points to give themselves a chance of staying up and two first-half goals from John Cavalli ensured their top-flight status.
Indeed, Caen were relegated instead after falling to a 3-1 defeat at Valenciennes. The home side went ahead on 36 minutes when Aboubakar headed home after a Remi Gomis corner.
Renaud Cohade came close to extending Valenciennes' lead early in the second half before Danic made it 2-0 from the penalty spot after Gomis was fouled by Thomas Heureux in the box. Caen gave themselves hope when Benjamin Nivet fired home on 77 minutes, but Renaud Cohade was sent clear to make it 3-1 to Valenciennes four minutes from time, and the news from Toulouse confirmed Caen's fate.
Dijon's Ligue 1 life also came to a shuddering halt after a crushing 5-0 defeat at Rennes condemned them to relegation. Goals by Victor Montano, Jires Ekoko (2), Jonathan Pitroipa and Youssouf Hadji saw Rennes to a sixth-placed finish - just outside the European berths.
Dijon lost their discipline as their fate became clear, losing both Younousse Sankhare and Chaher Zarour to red cards as they finished the campaign second-bottom after a dismissal nine-match winless run.
Issam Jomaa's second-half strike sealed Brest's top flight status for another season as Corentin Martins' side ended their campaign by claiming their second straight victory, 1-0 away to Evian.
Brest went into the game as one of eight sides who could still face relegation to Ligue 2, but knew a victory over their mid-table opponents would be enough to see them avoid the drop - and they did just that.
Sochaux also survived relegation with a last-day 1-0 victory over Marseille courtesy of Ryad Boudebouz's second-half strike. Boudebouz converted in the 55th minute as Sochaux, for so long the bottom side in the division, continued their late resurgence with the victory they needed to be sure of their top-flight status.
Bordeaux came through a five-goal thriller with St Etienne to cling on to fifth place and secure Europa League football. Rennes, St Etienne and Toulouse could all unseat them and they looked in big trouble when they fell behind to Josua Guilavogui's 19th-minute opener.
A quickfire Cheick Diabate double then put them in front but, when Pierre-Emerick Aubameyang levelled, it meant that Bordeaux were susceptible again. But Yoan Gouffran had one last contribution to make for the visitors, winning it with 22 minutes left to make sure it is his side who will be playing overseas next season.
Fourth-placed Lyon ended their campaign on a sour note after falling to a 4-3 defeat against Nice.
The hosts went ahead in the 21st minute through Lisandro Lopez before Jimmy Briand grabbed the first of his two goals five minutes later. The visitors were back on level terms before half time, however, through goals from Luciano Monzon and Kafoumba Coulibaly.
Nice took the lead for the first time after 53 minutes when Hugo Lloris could only turn the ball into his own net. Jimmy Briand then equalised in the 69th minute before Esmael Goncalves' goal decided matters in the 73rd minute.