Bayonne moved out of the bottom two with a bonus-point success over Stade Français.
The Basque side proved too powerful for the league leaders and gave their hopes of survival a major boost.
Elsewhere Toulouse held off a Lyon comeback to pick up an important win in the play-off race.
The games in Oyonnax and Grenoble were pushed back an hour because of the cold weather in the south east.
In the end Oyonnax downed Castres in a huge relegation clash, while Grenoble just held off Montpellier.
Bordeaux-Bègles 28-20 Toulon
Bayonne 23-6 Stade Français
Grenoble 20-18 Montpellier
Oyonnax 23-13 Castres
Toulouse 23-20 Lyon
Still to follow
Racing-Métro v Clermont
Bayonne 23-6 Stade Français
Stade Jean Dauger, Bayonne
Bayonne produced a powerful performance as they comfortably saw off Stade Français to move out of the bottom two.
Up against the leaders of the Top 14, they dominated from the off with their defence proving too strong for a Stade side that couldn't find a way through.
Bayonne needed a win and they made the perfect start with a try after just five minutes.
Having spent the opening exchanges defending in their own 22, Bayonne pounced on a dropped ball in midfield. Scott Spedding ran it back before releasing Mathieu Ugalde. The centre kicked the ball through with no Stade Français cover and Marvin O'Connor was the fastest to the ball to score.
Stade Français responded with a penalty from Julien Dupuy to cut the deficit to 5-3 but after 25 minutes Bayonne were over again.
After good work from the Basque forwards, Bayonne went through their three-quarters, with Spedding putting Joe Rokocoko over. This time Christophe Loustalot made the conversion, as Bayonne led 12-3 at the break.
Loustalot stretched the lead with another penalty early in the second half as Bayonne controlled matters.
An offside from Pelu Taele allowed Dupuy to add three points for Stade Français, and they should have had their first try just before the hour. After a turnover Jeremy Sinzelle countered before finding Jules Plisson. He kept the ball alive but with a huge overlap, Djibril Camara knocked on and the chance went begging.
With it seemed to go Stade's hopes of victory, and with 12 minutes to go they lost Rabah Slimani to a yellow card for a desperate infringement on his own line. Martin Bustos Moyano converted the penalty to make it 18-6.
The only remaining question was whether Bayonne could pick up all five points, and they got it through Jean Monribot after a maul from the Basques.
Tries: O'Connor, Rokocoko, Monribot
Pens: Loustalot, Bustos Moyano
Yellow Card: Senekal
For Stade Français:
Pens: Dupuy 2
Yellow Card: Slimani
Bayonne: 15 Scott Spedding, 14 Joe Rokocoko, 13 Matthieu Ugalde, 12 Gabiriele Lovobalavu, 11 Marvin O'Connor, 10 Santiago Fernandez, 9 Christophe Loustalot, 8 Charles Ollivon, 7 Jean Jo Marmouyet, 6 Jean Monribot, 5 Mark Chisholm, 4 Pelu Taele, 3 Aretz Iguiniz, 2 ,Anthony Etrillard 1 Janse Van Rensburg
Replacements: 16 David Roumieu, 17 Florian Lapeyrade, 18 Dewald Senekal, 19 Lisiate Fa'aoso, 20 Guillaume Rouet, 21 Martin Bustos Moyano, 22 Bastien Fuster, 23 Lucas Pointud
Stade Français: 15 Djibril Camara, 14 Julien Arias, 13 Jonathan Danty, 12 Meyer Bosman, 11 Jeremy Sinzelle, 10 Jules Plisson, 9 Julien Dupuy, 8 Raphael Lakafia, 7 Jono Ross, 6 Antoine Burban, 5 Gerhard Mostert, 4 Hugh Pyle, 3 Sakaria Taulafo, 2 Remi Bonfils, 1 Heinke van der Merwe
Replacements: 16 Talemaitoga Tuapati, 17 Aled De Malmanche, 18 Alexandre Flanquart, 19 Scott Lavalla, 20 Julien Tomas, 21 Morne Steyn, 22 Digby Ioane, 23 Rabah Slimani
Referee: Mathieu Raynal
Grenoble 20-18 Montpellier
Stade des Alpes, Grenoble
Grenoble edged a thriller in the snow at the Stade des Alpes thanks to Jonathan Wisniewski's late penalty.
Having taken the lead after just two minutes through Hendrik Roodt, Grenoble looked set to let the victory slip through their fingers.
However a late penalty at a ruck, which saw Teddy Iribaren sin-binned, allowed Wisniewski to slot the decisive penalty.
Roodt had opened the scoring with a try after good work from Rory Grice, before Ben Lucas opened the scoring for the visitors with a penalty.
While Wisniewski had been off-target with the conversion, he added two penalties to make it 11-3.
When Charl Mcleod was sin-binned Lucas cut the lead to five, before he added another penalty on the half-hour.
Wisniewski made it 14-9 at half-time with a drop goal before Grice was sin-binned for a tackle off the ball.
Jonathan Pelissié slotted Montpellier fourth penalty before Akapusi Qera was yellow-carded for the same offence as Grice.
Wisniewski made it 17-12 before Iribaren knocked over two late penalties to give Montpellier the lead for the first time.
He undid that good work with Grenoble on the attack though, and Wisniewski secured the vital win.
Pens: Wisniewski 4
Drop goals: Wisniewski
Yellow Cards: Mcleod, Grice
Pens: Lucas 3, Pelissie, Iribaren 2
Yellow Cards: Qera, Iribaren
Grenoble: 15 Gio Aplon, 14 Alipate Ratini, 13 Jackson Willison, 12 Nigel Hunt, 11 Julien Caminati, 10 Jonathan Wisniewski, 9 Charl Mcleod, 8 Rory Grice, 7 Fabien Alexandre, 6 Henry Vanderglas, 5 Hendrik Roodt, 4 Benjamin Hand, 3 Dayna Edwards, 2 Arnaud Héguy, 1 Fabien Barcella
Replacements: 16 Laurent Bouchet, 17 Denis Coulson, 18 Florian Faure, 19 Peter Kimlin, 20 Joannes Henry, 21 Chris Farrell, 22 Xavier Mignot, 23 Jono Owen
Montpellier: 15 Pierre Berard, 14 Timoci Nagusa, 13 Rene Ranger, 12 Anthony Tuitavake, 11 Lucas Dupont, 10 Benjamin Lucas, 9 Jonathan Pelissie, 8 Akapusi Qera, 7 Antoine Battut, 6 Fulgence Ouedraogo, 5 Thibaut Privat, 4 Sitaleki Timani, 3 Nicolas Mas, 2 Charles Geli, 1 Mikheil Nariashvili
Replacements: 16 Mickael Ivaldi, 17 Yvan Watremez, 18 Robins Tchale Watchou, 19 Alex Tulou, 20 Teddy Iribaren, 21 Enzo Selponi, 22 Wynand Olivier, 23 Pat Cilliers
Referee: Jérôme Garcès
Oyonnax 23-13 Castres
Stade Charles Mathon, Oyonnax
Oyonnax scored two tries either side of half-time to down Castres at Charles Mathon.
Castres had the better of the first half, scoring two penalties through Julien Dumora to open up a 6-0 lead.
However on the stroke of half-time Oyonnax broke through after a powerful scrum. Having got onto the front foot, Agustin Figuerola released Régis Lespinas who went over.
He converted to make it 7-6 at the break, and the home side added a second try early in the second half.
Again it followed good work from the home forwards, with Olivier Missoup dotting down after a good rolling maul. Lespinas converted once more.
Two more penalties in quick succession made it 20-6 to Oyonnax, who looked in complete control, but Castres hit back.
Remy Grosso made a great break before feeding Thomas Combezou inside him to go under the posts. Dumora's conversion made it a one-score game.
However another scrum penalty gave Lespinas the chance to knock over another penalty, and he gratefully accepted as Oyonnax comfortably saw out the game.
Tries: Lespinas, Missoup
Cons: Lespinas 2
Pens: Lespinas 3
Yellow Card: Jenneker
Pens: Dumora 2
Oyonnax: 15 Florian Denos, 14 Silvere Tian, 13 Pierre Aguillon, 12 Roimata Hansell Pune, 11 Yves Donguy, 10 Regis Lespinas, 9 Agustin Figuerola, 8 Viliami Ma'afu, 7 Olivier Missoup, 6 Maurie Fa'asavalu, 5 Damien Lagrange, 4 Thibault Lassalle, 3 Marc Clerc, 2 Jody Jenneker, 1 Antoine Tichit
Replacements: 16 Paula Ngauamo, 17 Ruaan Du Preez, 18 Leon Power, 19 Pedrie Wannenburg, 20 Fabien Cibray, 21 Valentin Ursache, 22 Adriaan Smit, 23 Soane Tonga'uiha
Castres: 15 Julien Dumora, 14 Max Evans, 13 Remi Lamerat, 12 Romain Cabannes, 11 Remy Grosso, 10 Remi Tales, 9 Cedric Garcia, 8 William Whetton, 7 Jannie Bornman, 6 Ibrahim Diarra, 5 Rodrigo Capo Ortega, 4 Christophe Samson, 3 Karena Wihongi, 2 Brice Mach, 1 Mihaita Lazar
Replacements: 16 Mathieu Bonello, 17 Yannick Forestier, 18 Benjamin Desroche, 19 Mathieu Babillot, 20 Antoine Dupont, 21 Daniel Kirkpatrick, 22 Thomas Combezou, 23 Ramiro Herrera
Referee: Laurent Cardona
Toulouse 23-20 Lyon
Stade Ernest Wallon, Toulouse
Toulouse held off a Lyon fightback to secure a narrow win that keeps them in contention in the play-off race.
After leading 20-9 at the break, they saw the ProD2 champions fight back, earning a well-deserved losing bonus point in the process.
In miserable conditions, Toulouse dominated the opening half, especially taking advantage of the Lyon scrum to earn a couple of early penalties. Toby Flood converted one, before the second led to a try for Joe Tekori.
After Yacouba Camara had scooped up the loose ball, he fed Gillian Galan. While the Toulouse number eight was stopped just short of the line, the third member of the back row finished the job as Tekori powered over.
Lyon, who were on the board through a Jérôme Porical penalty, were struggling in the lineout, and took off Jean-Philippe Bonrepaux after just half an hour. It made little difference though, with Toulouse scoring a wonderful team try.
Flood finished it off, but Bezy, Florian Fritz and Clément Poitrenaud had all been heavily involved in the build-up. Flood converted, as he had the first, to give Toulouse a 20-3 lead.
With five minutes left in the half, the heavens opened, making it difficult to play much rugby, and that continued into the second half.
And it was the visitors who started the second half with some impressive play in the sodden conditions.
After a series of mauls and charges from the forwards, the ball was finally spread, with Porical picking the perfect line to scoot past Maxime Médard and dot down. He converted his own try to bring the score back to 20-10.
Another penalty from Porical cut the deficit to seven points as Lyon came back into the game.
Toulouse needed to respond, and after a period of possession in Lyon territory they earned another penalty from a scrum, with Flood making it five from five to stretch the lead to 23-13.
Lyon kept coming though, but they showed a lack of patience trying twice to kick in the Toulouse 22 with the defence seemingly stretched.
That seemed to really hurt the visitors, and their task got tougher when they lost Kendrick Lynn to a yellow card with quarter of an hour remaining. After Edwin Maka had been tackled high, Lynn batted the ball out of Jean-Marc Doussain's hands and was duly binned as a result.
Toulouse still weren't completely dominant though, and Lyon fought back, with the home side having to shift Fritz into the back row after an injury to Patricio Albacete.
And after a powerful rolling maul, Damien Fitzpatrick emerged from the pile with the try. Lachie Munro converted and the deficit was cut to three points.
But the home side saw out the remaining couple of minutes to secure the four points and keep themselves in the play-off hunt.
Tries: Tekori, Flood
Cons: Flood 2
Pens: Flood 3
Tries: Porical, Balan
Cons: Porical, Munro
Pens: Porical 2
Yellow Card: Lynn
Toulouse: 15 Clément Poitrenaud, 14 Vincent Clerc, 13 Florian Fritz, 12 Gaël Fickou, 11 Maxime Médard, 10 Toby Flood, 9 Sébastien Bezy, 8 Gillian Galan, 7 Joe Tekori, 6 Yacouba Camara, 5 Patricio Albacete (c), 4 Grégory Lamboley, 3 Census Johnston, 2 Corey Flynn, 1 Gurthrö Steenkamp
Replacements: 16 Julien Marchand, 17 Schalk Ferreira, 18 Imanol Harinordoquy, 19 Yannick Nyanga, 20 Jean-Marc Doussain, 21 Yann David, 22 Timoci Matanavou, 23 Neemia Tialata
Lyon: 15 Jérôme Porical, 14 Franck Romanet, 13 Kendrick Lynn, 12 Fabrice Estebanez, 11 Mosese Ratuvou, 10 Lachie Munro, 9 Mathieu Lorée, 8 Juan Leguizamon, 7 Deon Fourie, 6 Julien Puricelli, 5 Lionel Nallet (c), 4 Mickaël De Marco, 3 Francisco Tetaz, 2 Jean-Philippe Bonrepaux, 1 Emmanuel Felsina
Replacements: 16 Damien Fitzpatrick, 17 Bogdan Balan, 18 Karim Ghezal, 19 Simon Njewel, 20 Ricky Januarie, 21 Romain Loursac, 22 Paul Bonnefond, 23 Hoani Tui
Referee: Salim Attalah