Clermont dropped their first points of the season as they were surprisingly held to a draw at home by Bordeaux-Bègles.
Elsewhere, Racing 92 edged past Grenoble while Montpellier hammered Stade Français.
Earlier in the day Toulon had comfortably seen off La Rochelle at Mayol.
Castres 35-26 Oyonnax
Toulon 45-24 La Rochelle
Racing 92 23-14 Grenoble
Montpellier 44-20 Stade Français
Clermont 26-26 Bordeaux-Bègles
Brive v Agen
Pau v Toulouse
Racing 92 23-14 Grenoble
Stade Yves du Manoir, Colombes
Racing 92 came from behind to pick up an important victory at home to Grenoble.
Grenoble started much the quicker, opening up an 8-0 lead thanks to a Jonathan Wisniewski penalty, quickly followed by a try from Armand Batlle. The former Perpignan winger popped up from first phase, squeezing past Henry Chavancy and Sean Robinson for the score.
Maxime Machenaud kept his side in touch with two penalties, either side of one from Wisniewski, as Grenoble led 11-6 midway through the half.
But the momentum had shifted back towards the home side and they then took advantage of some loose play from Grenoble, Joe Rokocoko picking off a pass in midfield and sprinting 40 metres for the interception try. Machenaud converted to make it 13-11 to Racing.
On the stroke of half-time Machenaud added three more points as Racing finished the half the stronger, with a five-point lead.
Wisniewski cut the deficit to two points but was soon sin-binned for kicking the ball away from Chris Masoe.
Racing took advantage, running in their second try, through youngster Xavier Chauveau after great work from the Racing pack. Machenaud converted and the hosts led 23-14.
Grenoble weren't done though, and after a succession of infringements, Thibault Dubarry was sin-binned for Racing, although a potential try was disallowed by the TMO with the ball not visible after crossing the line.
And they had a second try ruled out, with Gio Aplon knocking on over the line after a clever grubber through from Arnaud Héguy, with Racing holding on and denying their visitors a bonus point.
For Racing 92:
Tries: Rokocoko, Chauveau
Cons: Machenaud 2
Pens: Machenaud 3
Yellow Card: Dubarry
Pens: Wisniewski 2
Yellow Card: Wisniewski
Racing 92: 15 Sean Robinson, 14 Joe Rokocoko, 13 Etienne Dussartre, 12 Henry Chavancy, 11 Marc Andreu, 10 Benjamin Dambielle, 9 Maxime Machenaud, 8 Chris Masoe, 7 Thibault Dubarry, 6 Wenceslas Lauret, 5 Francois van der Merwe, 4 Manuel Carizza, 3 Luc Ducalcon, 2 Camille Chat, 1 Davit Khinchagishvili.
Replacements: 16 Armand van der Merwe, 17 Julien Brugnaut, 18 Juandre Kruger, 19 Antonie Claassen, 20 Xavier Chauveau, 21 Casey Laulala, 22 Luc Barba, 23 Cedate Gomes Sa.
Grenoble: 15 Gio Aplon, 14 Xavier Mignot, 13 Fabrice Estebanez, 12 Nigel Hunt, 11 Armand Batlle, 10 Jonathan Wisniewski, 9 Charl Mcleod, 8 Rory Grice, 7 Jonathan Best, 6 Steven Setephano, 5 Hendrik Roodt, 4 Benjamin Hand, 3 Dayna Edwards, 2 Arnaud Heguy, 1 Denis Coulson.
Replacements: 16 Anthony Hegarty, 17 Rossouw De klerk, 18 Mathias Marie, 19 Peter Kimlin, 20 Christophe Loustalot, 21 Fabien Gengenbacher, 22 Chris Farrell, 23 Walter Desmaison.
Referee: Salem Attalah
Montpellier 44-20 Stade Français
Altrad Stadium, Montpellier
Montpellier continued their fine start to the season with a convincing win over Stade Français, handing the champions a third loss in a row.
Montpellier took the lead early on with two penalties from Benoit Paillaugue, but they were cancelled out by two from Jules Plisson, as the teams were level after half an hour.
The final ten minutes of the half were all Montpellier though, and they ran in three tries to take control of the game.
First Marvin O'Connor crossed, with Paillaugue feeding him following a powerful rolling maul. The scrum-half converted to make it 13-6.
And O'Connor added a second try four minutes later, popping up in support after Benjamin Fall had collected a high ball before passing to François Trinh-Duc, who found his winger. Paillaugue was again on target with the touchline conversion.
There was time for one more before the break, as Plisson's long pass was intercepted by Timoci Nagusa, who sprinted away, and with the conversion, Montpellier led 27-6 at half-time.
The Montpellier pack continued to dominate in the second-half, and Paul Willemse took advantage to power over just before the hour, with Paillaugue again converting.
Stade replied with a try of their own, Meyer Bosman the man to cross, but it was only temporary respite with Willemse grabbing his second after another rolling maul.
After O'Connor and Willemse, it was Nagusa's turn to score a brace, after an interception by O'Connor saw him away and while the defence got back, he found the Fijian outside him for the score.
Stade hit back, scoring a second try as Montpellier pulled down a maul that was headed towards their line, conceding a penalty try in the process. Plisson converted his second try of the afternoon but it was scant consolation.
Tries: O'Connor 2, Nagusa 2, Willemse 2
Cons: Paillaugue 4
Pens: Paillaugue 2
For Stade Français:
Tries: Bosman, Penalty
Cons: Plisson 2
Montpellier: 15 Anthony Floch, 14 Benjamin Fall, 13 Timoci Nagusa, 12 Andrew Smith, 11 Marvin O'Connor, 10 Francois Trinh-Duc, 9 Benoit Paillaugue, 8 Kelian Galletier, 7 Ben Mowen, 6 Sitaleki Timani, 5 Paul Willemse, 4 Robins Tchale Watchou, 3 Pat Cilliers, 2 Mickael Ivaldi, 1 Yvan Watremez.
Replacements: 16 Charles Geli, 17 Schalk Van der Merwe, 18 Antoine Battut, 19 Willem Liebenberg, 20 Nic White, 21 Ben Lucas, 22 Julien Malzieu, 23 Jacobus Adriaanse,
Stade Français: 15 Djibril Camara, 14 Hugo Bonneval, 13 Geoffrey Doumayrou, 12 Paul Williams, 11 Jeremy Sinzelle, 10 Jules Plisson, 9 Julien Dupuy, 8 Jono Ross, 7 Matthieu Ugena, 6 Sylvain Nicolas, 5 Tomas Vallejos, 4 Paul Gabrillagues, 3 Paul Alo-Emile, 2 Rémi Bonfils, 1 Heinke Van der Merwe.
Replacements: 16 Laurent Panis, 17 Dany Priso Mouangue, 18 Gerhard Mostert, 19 Patrick Laurence Sio, 20 Julien Tomas, 21 Meyer Bosman, 22 Jonathan Danty, 23 Giorgi Melikidze.
Referee: Maxime Chalon
Clermont 26-26 Bordeaux-Bègles
Stade Marcel Michelin, Clermont-Ferrand
Clermont came from behind to earn a draw at home to Bordeaux-Bègles, but struggled to produce their best form as they failed to win for the first time this season.
With 15 points from three games to start the season, Clermont were the form team in the league, but it was Bordeaux who flew out of the blocks.
They scored after just 90 seconds, with Peter Saili powering through before offloading for young number eight Marco Tauleigne to race over, brushing off Enzo Sanga on his way to the line.
Baptiste Serin missed the conversion, but popped up for the second try, after Jean-Marcellin Buttin had collected a high ball in the 22 at his former club. The ball was spread quickly and Serin crossed in the left corner.
The young scrum-half, shifted out to fly-half for this game, converted from the touchline, to make it 12-0 to the visitors.
Clermont were shell-shocked, but had the chance to cut the deficit when Camille Lopez had a long-range penalty attempt. He pulled that wide, but made up for it midway through the half with a tough kick to make it 12-3.
The home side looked to have recovered, and worked their way into the Bordeaux 22. However when they got up to the line, Bordeaux turned it over, with the help of a boot into the hands of Sanga, and Felix Le Bourhuis fed Nans Ducuing for the long-range counter-attacking try. Serin hit the post with the conversion but Bordeaux led 17-3.
A second Lopez penalty cut the deficit, and after he was forced off injured, Patricio Fernandez took over and slotted another penalty just before the break.
Bordeaux scored first in the second-half, with a penalty from Serin, although he then had to be replaced after pulling a muscle as he rejoined his partners.
Clermont were not about to fold though and after a half-break from Fernandez, Aurélien Rougerie was on hand to power over, just stretching to dot down on the line. With the conversion from Fernandez, the lead was cut to just seven points with 25 minutes remaining.
And they were soon level, taking advantage of a mistake under the high ball from the visitors. The ball was quickly spread and Nick Abendanon spun out of one tackle before sprinting under the posts.
Abendanon was at it again, breaking out of his own 22 to set up more points, with Jean-Baptiste Dubié isolated and conceding a penalty. Fernandez did the honours to make it 26-23 as Clermont led for the first time.
Sébastien Vahaamahina was then caught coming in from the side at a maul, handing Pierre Bernard the chance to level the scores, and he took full advantage.
Clermont thought they had a third try when Lee went over after a kick through from Fernandez, but Paul Jedrasiak was caught pushing Ducuing in the build-up.
And although Clermont kept coming, they couldn't find a way through, having to settle for two points in the end.
Tries: Rougerie, Abendanon
Cons: Fernandez 2
Pens: Lopez 2, Fernandez 2
Tries: Tauleigne, Serin, Ducuing
Pens: Serin, Bernard
Clermont: 15 Nick Abendanon, 14 David Strettle, 13 Aurelien Rougerie, 12 Hosea Gear, 11 Adrien Plante, 10 Camille Lopez, 9 Enzo Sanga, 8 Fritz Lee, 7 Julien Bardy, 6 Camille Gerondeau, 5 Sebastien Vahaamahina, 4 Paul Jedrasiak, 3 Daniel Kotze, 2 Marthinus van der Westhuizen, 1 Thomas Domingo.
Replacements: 16 Iuri Natriashvili, 17 Raphael Chaume, 18 Arthur Iturria, 19 Alexandre Lapandry, 20 Jeanbaptiste Bruzulier, 21 Patricio Fernandez Fiant, 22 Albert Vulivuli, 23 Clement Ric,
Bordeaux-Bègles: 15 Jean-Marcellin Buttin, 14 Jean-Baptiste Dubié, 13 Felix Le Bourhis, 12 Julien Rey, 11 Nans Ducuing, 10 Baptiste Serin, 9 Heini Adams, 8 Marco Tauleigne, 7 Peter Saili, 6 Louis Benoit Madaule, 5 Berend Botha, 4 Julien Ledevedec, 3 Francisco Gomez Kodela, 2 Benat Auzqui, 1 Jefferson Poirot.
Replacements: 16 Clement Maynadier, 17 Jean Baptiste Poux, 18 Adam Jaulhac, 19 Loann Goujon, 20 Hugh Chalmers, 21 Pierre Bernard, 22 Charles Brousse, 23 Albert Toetu.
Referee: Thomas Charabas