Toulon's climb up the Top 14 table was arrested by Castres Olympique on Saturday afternoon, as the home team prevailed 34-19 at the Stade Jean-Pierre Antoine.
Two early Pierre Bernard penalties saw the visitors into a 6-0 lead, but a 17th minute try to Robert Ebersohn was then converted by Geoffrey Palis - who would put together a 19-point haul on the day - and it was the hosts who led 13-9 at half-time.
Ebersohn crossed for his second try of the game just after the break, and it was Palis himself taking the score out to 25-12 in the 55th minute after converting his own try.
Jean Charles Orioli struck in the 59th minute for the visitors sole five-pointer, but in the end it fell to substitute Tudor Stroe to seal a big win for Castres with his try shortly before the final whistle.
Ill discipline cost Montpellier in Sunday's Top 14 clash as Stade Francais fly-half Jules Plisson kicked seven penalties in a 21-17 win at Stade Jean Bouin in Paris.
Montpellier trailed 9-3 at the break, but got themselves back into the contest through two tries in the space of five minutes from Australian international Joe Tomane and Fijian winger Timoci Nagusa.
Montpellier's hard work was undone though as they continued to concede penalties and Plisson made them pay.
It's Stade Francais fifth win of the season, moving them up to tenth ahead of Lyon.
A solitary second-half penalty from Manu Saubusse was the difference as Bayonne beat Toulouse 16-13 on Sunday.
A Gillian Galan try inside six minutes saw Toulouse lead, but the game was level 13-13 at the break. In a less than uneventful second-half Florian Fritz was sin-binned to give Saubusse the opportunity to give Bayonne the winning penalty six minutes after the restart.
A Morgan Parra penalty in injury times gave Clermont a 16-13 victory over Lyon at the Stade Marcel-Michelin.
Jacques-Louis Potgieter kicked Lyon ahead 11 minutes in, but two kicks from Parra saw Clermont lead 6-3 at the break. Arthur Iturria jotted down after the break, a try which Parra converted. But a Potgieter penalty and his conversion to Baptiste Couilloud's try 15 minutes from time looked to have sealed a draw for Lyon.
But there was late drama as Mickael Ivaldi was sin-binned in injury-time and Parra converted the penalty for the win.
Racing 92 defeated Grenoble 29-24 in a try-fest in Paris. Yannick Nyanga crossed for Racing inside six minutes but was cancelled out four minutes later as Fabien Alexandre touched down.
Dimitri Szarzewski put Racing back in front on the half hour, as James Hart converted, who led 14-10 at half-time as a Jonathan Wisniewski penalty narrowed the margin.
Grenoble, who have managed just two wins this season led when Laurent Bouchet's try was converted four minutes after the restart.
The lead lasted 10 minutes before Francois van der Merwe crashed over and Henry Chavancy sealed the result with a fourth Racing try 15 minutes from time.
Simon Hickey kicked 14 points as Bordeaux Begles leapfrogged La Rochelle into second in the table after a 26-0 victory.
But it was closer than the result suggests as Hickey kept the scoreboard ticking over at every opportunity for a 6-0 half-time lead. He added two penalties and conversion to Sebastien Taofifenua's try on the hour to stretch their lead.
Front row replacement Jean-Baptiste Poux touched down two minutes from time for a convincing win.
Brive climbed to ninth as they brushed the challenge of Pau aside, 38-25. A converted Benjamin Lapeyre try and penalty from Gaetan Germain saw Brive lead 10-3 before Charly Malie pulled a try back for Pau who trailed 13-8 at the break.
Both sides saw two players sin-binned in the second-half as tries from Seremaia Burotu, Nicolas Bezy and Takudzwa Ngwenya saw them to victory. Pau added consolation tries through Chris King and Marvin Lestremau in the final 10 minutes.