The Top 14 standings were given a major shake-up on Saturday as Biarritz and Toulouse both lost, allowing Clermont to climb into second place.
Biarritz's four-game winning streak came to an end in Castres meaning Toulon are now four points clear at the top of the table.
Clermont needed a late try from Naipolioni Nalaga to beat Mont-de-Marsan, who are still without a point.
The big winners of the day were Racing, who claimed a crucial win on the road in Bayonne to break into the top half of the standings.
Agen bagged their first win of the season against Grenoble, who continue to surprise after claiming a losing bonus point.
In the Saturday's late game, Stade FranÃ§ais were sent back to the capital empty handed by Bordeaux-BÃ¨gles.
Earlier in the day, Perpignan thumped defending champions Toulouse in Barcelona.
Montpellier 25-32 Toulon - match report here
Perpignan v Toulouse - match report here
Agen 32-26 Grenoble
Bayonne 18-25 Racing MÃ©tro
Castres 28-13 Biarritz
Mont-de-Marsan 6-14 Clermont
Bordeaux-BÃ¨gles 30-22 Stade FranÃ§ais
Aviron Bayonnais 18-25 Racing-MÃ©tro 92
Stade Jean Dauger, Bayonne
After being denied at the death in Clermont last week, Racing finally got their away victory on Saturday but they left it very late.
Bayonne led 15-12 at half time as the opposing place-kickers traded three-pointers.
After the scores were locked at 15-all on the hour mark, South African lock Francois Van der merwe crashed over the 12 minutes left to play to secure victory for les Franciliens.
Pens: Potgeiter 5, Boyet
Try: Van der Merwe
Pens: Germain 6
Yellow cards: Brugnaut (Racing - 18th min- high tackle); Ahoateiloa (Bayonne - 58th min - ruck infringements)
Bayonne: 15 Scott Spedding, 14 Sam Gerber, 13 Manu Ahotaeiloa, 12 Lionel Mazars, 11 Joe Rokocoko, 10 Jacques Louis Potgeiter, 9 Mike Phillips, 8 Julien Puricelli , 7 Mark Chisholm, 6 Guillaume Bernad, 5 Abdellatif Boutaty, 4 Dewald Senekal, 3 Renaud Boyoud, 2 David Roumieu , 1 Aretz Iguiniz,
Replacements: 16 Gregory Arganese, 17 Vitolio Manukula, 18 Dwayne Haare, 19 Marc Baget, 20 Cedric Garcia, 21 Benjamin Boyet , 22 Cedric Heymans, 23 Pierre Lafond
Racing-MÃ©tro: 15 Gaetan Germain 14 Virimi Vakatawa 13 Henry Chavancy 12 Guillaume Bousses 11 Julien Jane 10 Mathieu Belie 9 Maxime Machenaud 8 Masinivanua Matadigo 7 Bernard Le roux 6 Camille Gerondeau 5 Karim Ghezal 4 Santiago Dellape 3 Salemane Sa 2 Dimitri Szarzewski 1 Julien Brugnaut
Replacements: 16 Benjamin Noirot 17 Eddy Ben arous 18 Francois Van der merwe 19 Jone Qovu, 20 Mirco Bergamasco 21 Fabrice Estebanez 22 Antoine Battut 23 Luc Ducalcon
Stade Montois 6-14 ASM Clermont Auvergne
Stade Guy Boniface, Mont-de-Marsan
It wasn't pretty but Clermont got the job done in the end to deny Mont-de-Marsan their first points of the season.
It was all square at 3-3 at half time and 6-6 going into the final ten minutes.
But Naipolioni Nalaga got Clermont out of jail with a try three minutes from time after Benson Stanely and broken through the home defence.
Pens: Claverie 2
Pens: Radosavljevic , James
Mont-de-Marsan:15 Simon Lucu, 14 Martin Jagr, 13 Baptiste Chedal, 12 Daniele Baleinadogo, 11 Jean baptiste Dubie, 10 Jean baptiste Claverie, 9 Arnaud Pic, 8 Haisini Taulanga , 7 Sebastian De chaves, 6 Julien Tastet, 5 Berend Botha, 4 Scott Murray, 3 Sebastien Ormaechea, 2 Thomas Bordes , 1 Alexandre Menini,
Replacements: 16 Pieter Grobler, 17 Julian Fiorini, 18 Philipus Liebenberg, 19 Alexandre Ricaud, 20 Julien Cabannes, 21 William Ryder , 22 Yohann Durquet, 23 Tevita Mailau,
Clermont:15 Lee Byrne, 14 Jean Marcellin Buttin, 13 Aurelien Rougerie, 12 Regan King, 11 Naipolioni Nalaga, 10 David Skrela, 9 Ludovic Radosavljevic, 8 Elvis Vermeulen, 7 Julien Bardy, 6 Julien Bonnaire, 5 Julien Pierre, 4 Jamie Cudmore, 3 Daniel Kotze, 2 Benoit Cabello, 1 Raphael Chaume.
Replacements: 16 Ti'i Paulo 17 Thomas Domingo 18 Loic Jacquet 19 Viktor Kolelishvili 20 Morgan Parra 21 Brock James 22 Benson Stanley 23 Davit Zirakashvili
Castres Olympique 28-13 Biarritz Olympique
Stade Pierre Antoine, Castres
Biarritz were fianlly brought back down to earth.
South African scrum-half Rory Kockott came off the bench to star for Castres, finishing with 16 points from a converted try and three penalties.
Biarritz led 13-12 at half time thanks to an early try from fly-half Julien Peyrelongue
The complexion of the game changed totally after the interval as CO upped the tempo and Biarritz were unable to keep up with given away penalties and yellow cards.
Pens: Teulet 4, Kockott 3
Pens: Peyrelongue, Baby
Yellow cards: Lauret (Biarritz - 45th min - ruck infringements); Barcella (Biarritz - 54th min - professional foul); Kockott (Castres - 76th min - offside); Taumeopeau (Castres - 77th min - scrum infringements)
Castres:15 Brice Dulin, 14 Marcel Garvey, 13 Romain Cabannes, 12 Maxwell Evans, 11 Marc Andreu, 10 Remi Tales, 9 Romain Teulet, 8 Antonie Claassen , 7 Yannick Caballero, 6 Jan de bruin Bornman, 5 Iosefa Tekori, 4 Christophe Samson, 3 Karena Wihongi, 2 Mathieu Bonello , 1 Yannick Forestier,
Replacements: 16 Brice Mach, 17 Saimone Taumoepeau, 18 Piula Faasalele, 19 Pedrie Wannenburg, 20 Rory Kockott, 21 Pierre Bernard , 22 Romain Martial, 23 Michael Coetzee
Biarritz:15 Iain Balshaw, 14 Takudzwa Ngwenya, 13 Dane Haylett petty, 12 Damien Traille, 11 Benoit Baby, 10 Julien Peyrelongue, 9 Yann Lesgourgues, 8 Raphael Lakafia, 7 Wenceslas Lauret, 6 Magnus Lund, 5 Pelu ian Taele, 4 Erik Lund, 3 Francisco Gomez Kodela, 2 Jean philippe Genevois, 1 Fabien Barcella.
Replacements: 16 Benoit August, 17 Thomas Synaeghel, 18 Jerome Thion, 19 Benoit Guyot, 20 Jean pascal Barraque, 21 Seremaia nakala Burotu, 22 Aled Brew, 23 Benedict Broster.
SU Agen 32-26 FC Grenoble
Stade Armandie, Agen
Agen finally get their first win of the season but it was close-run affair with Grenoble hanging on gamely.
Agen led 23-13 at half time but 23-23 after 53 minutes!
But the hosts could count on the reliable boot of