The champions ended a brilliant year in disappointing fashion as elsewhere, Rennes moved up to fourth with a 4-2 win, and Bastia beat struggling Nancy with the same scoreline
Montpellier ended a glorious calendar year, in which they were crowned league winners for the first time with a dispiriting 4-1 defeat away to Lille at Grand Stade Lille Metropole.
The hosts, who themselves wanted to cap off a disappointing year, started brightly when Nolan Roux fired in the opener after good work from Dimitri Payet.
Payet turned goalscorer with a fine finish soon after, his third goal in as many games, before Younes Belhanda saw a straight red card after challenging Benoit Pedretti - earning his second dismissal in just over a month.
After the break, Roux again took advantage of some lax defending to beat Geoffrey Jourdren, before Ryan Mendes extended the hosts' lead to 4-0, converting in from Marvin Martin's pass behind the defence.
Souleymane Camara earned a consolation goal for the visitors with seven minutes left on the clock, though, it is Lille who shoot up to fifth place.
AC AJACCIO 2-4 STADE RENNAIS
Rennes rose to fourth place in the table after an entertaining 4-2 victory over coachless Ajaccio at Stade Francois Coty on Saturday.
The hosts, who fired manager Alex Dupont earlier in the week, to be replaced by former Marseille boss Albert Emon in January, took the lead early on through Adrian Mutu, whose fine volley beat Benoit Costil
Fousseini Diawara handballed in the box, as Julian Feret equalised from the spot, but Diawara turned from zero to hero, heading in from Johan Cavalli's delivery.
Romain Alessandrini maintained his high-quality finishing this season with a fantastic free-kick from distance just before half-time, before Sigamarry Diarra made it 3-2 in the second half.
The fourth goal proved controversial as the referee awarded a free-kick inside the penalty area after an illegal backpass, amid crowd unrest in Corsica, but Feret struck his second of the night to cap off a remarkable game.
FC LORIENT 2-2 STADE DE REIMS
Lorient ruined Reims' hopes of a first win since early October as they struck in injury time to draw 2-2 and maintain fifth place at Stade du Moustoir.
The visitors took a shock lead against the in-form Merlus as Odair Fortes found the net after just six minutes of play on Saturday.
Maxime Barthelme equalised for Christian Gourcuff's men, though, they fell behind again as Gaetan Courtet found the net for Hubert Fournier's visitors on 70 minutes.
Nevertheless, Lorient maintained their five-game unbeaten run with a late strike from defender Pedrinho, as he condemned Reims to yet another game without a win, as they sit precariously above the drop zone.
GIRONDINS DE BORDEAUX 0-0 ESTAC TROYES
Bordeaux picked up their 11th draw in 19 Ligue 1 games so far this season, as they were frustratingly held once more against struggling Troyes.
The game's conclusion was met with furious boos by the Stade Cheban-Delmas faithful in the south-west, after yet another stalemate - the club's fifth in a row.
Yohann Thuram-Ulien denied the hosts with a string of terrific blocks, including from Nicolas Maurice-Belay, Gregory Sertic and most notably from Ludovic Sane, whose header was stopped in point-blank range by the young goalkeeper.
At the other end, Mohamed Yattara was denied by Cedric Carrasso, but the lack of potent finishing from Francis Gillot's men hurt them once more as they slipped further off the pace.
OLYMPIQUE LYONNAIS 3-0 OGC NICE
Lyon moved level on points with leaders Paris Saint-Germain with a comfortable 3-0 win over high-flying Nice, who suffered their first defeat in nine at Stade Gerland.
The visitors' coach Claude Puel was met with unkind boos from the home faithful, having been at the helm of the club from 2008-11, though his side were denied by a fantastic stop by Remy Vercoutre early on.
Lyon went ahead after Lisandro Lopez tapped-in from Bafetimbi Gomis' fine cut-back, before Anthony Reveillere struck his first league goal in almost five years in the second half.
Dario Cvitanich, Nice's saviour this season, produced a howler of a miss, firing wide when he should've found the back of the net, and the side were punished as goalkeeper David Ospina was shown red for a horrible challenge on Gomis.
The dreadlocked striker scored from the spot to round off a promising start to the season, though, not before Dejan Lovren was sent off for a second bookable offence in the 90th minute.
SC BASTIA 4-2 AS NANCY
Nancy will spend Christmas and New Year rooted firmly to the bottom of the Ligue 1 table as they suffered a demoralising 4-2 defeat to Bastia.
Having not won since the opening day of the season, Jean Fernandez's men entered the game with hopes of reducing the deficit between them and 18th placed Sochaux, but they were well beaten by their fellow relegation strugglers in a match played away from Bastia's Stade Armand Cesari due to an indefinite ban.
Bastia raced into a commanding lead early on thanks to goals from Jerome Rothen, Anthony Modeste and Sambou Yatabare inside the first 26 minutes, leaving Nancy with a plethora of problems to contend with.
Benjamin Moukandjo appeared to start a comeback soon after the re-start after reducing the scoreline to 3-1, but Modeste struck again to further extend the hosts' lead, before Andre Luiz fired in a consolation effort after 77 minutes to leave ASNL needing an early miracle in 2013 to avoid the drop.
VALENCIENNES 2-1 EVIAN
Valenciennes brought a promising 2012 to an end with victory over Evian at Stade du Hainaut in the Sunday afternoon kick-off.
Daniel Sanchez celebrated extending his contract with the club as they picked up their first win in four games to move upto sixth place as ten-man Evian were beaten.
Gregory Pujol broke the deadlock with a controlling finish after Rudy Mater's cross was helped on by Aldo Angoua. Saber Khelifa equalised for the Annecy side, being set-up by Yannick Sagbo as the Tunisia international restored parity.
Djakirdja Kone was shown a straight red card for a crushing challenge midway through the second half, before Jose Saez put Valenciennes in front, but only after Mathieu Dossevi missed from the spot.
TOULOUSE FC 2-0 SOCHAUX
Toulouse avoided slipping further down the table with a welcome 2-0 victory over struggling Sochaux, who remain in the bottom three.
Adrien Regattin opened the scoring with a fine free-kick after Jerome Roussillon's handball, as the hosts finally ended their long goal drought.
Sochaux exemplified their low standing with a toothless performance, and they were further punished late on as Emmanuel Riviere supplied the finish after a good pass from Etienne Didot.
Toulouse sit in 12th place, four points ahead of Bastia, though only six behind fourth-placed Rennes in a tight table.
OLYMPIQUE DE MARSEILLE 1-0 SAINT-ETIENNE
Marseille picked up their third consecutive win as they ended a turbulent year on and off the pitch with a narrow 1-0 win over Saint-Etienne in a turgid encounter at Stade Velodrome.
The game's only goal was scored by Andre Ayew, who beautifully produced a powerful header from Rod Fanni's measured cross to seal the win for Elie Baup's men.
The visitors couldn't test Steve Mandanda in the Marseille goal, with Pierre Emerick Aubameyang and Joshua Guilavogui denied by the France international.
It enabled Marseille to pick up their third consecutive win, and 12th overall this season - more than any other side in Ligue 1, as they moved level on points with PSG and Lyon at the top.