Castres consolidated their lead of the French Top 14 with a six-try drubbing of Albi as Stade Francais stuttered to a drab 6-6 draw with Montauban.
Clermont moved into second place with an impressive five-try 39-3 dismantling of Toulon.
Fourth placed Racing-Metro, who last lost in September, were denied a 10th successive win by Bourgoin, who triumphed 18-17 in the French capital.
Former European champions Toulouse moved into third place with a 15-13 win at second-bottom Bayonne.
Fifth-placed Perpignan, the defending champions, suffered a shock 29-9 defeat to Brive.
Biarritz sealed a much-needed win over Montpellier, scoring four tries to one in a 26-10 victory that saw them up to sixth spot.
