Perpignan slumped to their third consecutive Top 14 defeat on Saturday despite scoring four tries at Clermont.
Toulon scored their third straight win on the road in Mont-de-Marsan, where they also collected a bonus point to move level at the top of the standings with Biarritz.
Montpellier ran four tries past Agen to secure a bonus point while Castres scored three tries in their second consecutive win at home over Bayonne.
Racing couldn't get over the whitewash but were nevertheless too strong for Bordeaux-Bègles in Paris.
Earlier in the day, Biarritz stayed top of the table thanks to victory over Toulouse.
ASM Clermont Auvergne 53-31 USA Perpignan
A crazy game as Clermont outscored USAP seven tries to four to climb.
Perpignan's evening got off to the worst possible start when veteran prop Nicolas Mas was forced off after just five minutes with a torn hamstring. He is expected to be out for six to eight weeks
The result never looked in doubt when Clermont headed to the changing rooms with a 27-10 lead. But when Luke Narraway and Lifeimi Maf touched down in the space of four minutes, it looked like the hosts might miss out on the bonus despite their six tries.
But Julien Bonnaire's second try of the afternoon ensured that Clermont would get all five points and climb into the leading trio.
Castres Olympique 31-10 Aviron Bayonnais
A dominant performance from Castres underlined their credentials as play-off contenders.
Jean Marmouyet's early score gave Bayonne a 7-0 lead but Castres soon took control of the match to record their second win.
Another excellent kicking display from Rory Kockott and two well-worked second half tries from wing Romain Martial and lock Rodrigo Capo Ortega ensured victory for CO.
Montpellier Herault Rugby 32-15 SU Agen
Montpellier backed-up their win over Clermont last week with a bonus-point victory at home.
The hosts led 10-3 at the break but Agen competed well and it was anyone's game at the hour mark.
However three tries in the last quarter ( Carraro, Nagusa, Tomas) ensured that Montpellier finished the weekend in the top half of the standings.
Racing-Metro 18-7 Union Bordeaux-Begles
It wasn't pretty but Racing were pateint enough to get the job done, thanks to the accurate goal-kicking of full-back Gaetan Germain, who landed all the hosts points from the tee.
UBB scored the only try of the game in the 78th minutes when lock Cameron Treloar finished off a 100m long counter attack, thanks to super work from centre Andrew Mailei.Bordeaux-Bègles:15 Bruce Reihana, 14 Thierry Brana, 13 Felix Le bourhis, 12 Andrew Mailei, 11 Blair Connor, 10 Camille Lopez, 9 Heini Adams, 8 Matthew Clarkin, 7 Hugh Chalmers, 6 Gautier Gibouin, 5 Francois Tisseau, 4 Cameron Treloar, 3 Silviu Florea, 2 Fabien Rofes, 1 Jefferson Poirot.
Replacements: 16 Wayne Avei, 17 Laurent Delboulbes, 18 Adam Jaulhac, 19 Sisa Koyamaibole, 20 Emmanuel Saubusse, 21 Metuisela Talebulamaijaina, 22 Darly Domvo, 23 Albert Toetu.
Stade Montois 15-29 RC Toulon
Stade Guy Boniface, Mont-de-Marsan
Mont-de-Marsan enjoyed territorial dominance in the first half but Toulon led 14-12 at the break thanks to a try from Steffon Armitage.
Toulon looked in a spot of bother when Thibault Duvallet landed his fifth penalty to put the hosts in front on 65 minutes.
But two late tries courtesy of the Toulon back row bagged a bonus point and the joint championship lead for Bernard Laporte's army.
Pens: Duvallet 5
Tries: S.Armitage, Van Niekerk, Gunther
Pens: Wilkinson 2
Yellow cards: Botha (Toulon - 80th min - high tackle)
Mont-de-Marsan:15 Yohann Durquet, 14 Martin Jagr, 13 Jean baptiste Dubie, 12 Baptiste Chedal, 11 Nicholas Price, 10 Thibault Duvallet , 9 Arnaud Pic, 8 Alexandre Ricaud, 7 Johannes Britz, 6 Julien Tastet, 5 Berend Botha, 4 Sebastian De chaves, 3 Sebastien Ormaechea, 2 Joan Caudullo, 1 Alexandre Menini.
Replacements: 16 Pieter Grobler, 17 Pierre Correia, 18 Philipus Liebenberg, 19 Haisini Taulanga, 20 Laurent Magnaval, 21 Julien Cabannes, 22 Bernard Arrayet, 23 Tevita Mailau.
Toulon:15 Delon Armitage, 14 Vincent Martin, 13 Mathieu Bastareaud, 12 Maxime Mermoz, 11 Benjamin Lapeyre, 10 Jonny Wilkinson, 9 Nicolas Durand, 8 Joe Van niekerk, 7 Steffon Armitage, 6 Pierrick Gunther, 5 Jocelino Suta, 4 Bakkies Botha, 3 Davit Kubriashvili, 2 Sebastien Bruno, 1 Andrew Sheridan.
Replacements: 16 Mickael Ivaldi, 17 Gethin Jenkins, 18 Simon Shaw, 19 Nicholas Kennedy, 20 Matthew Giteau, 21 Luke Rooney, 22 Frederic Michalak, 23 Carl Hayman.