Paris - Castres' Argentinan flyhalf Benjamin Urdapilleta orchestrated a six-try, 52-7 thrashing of Toulouse on Saturday that deprived the 19-time French championship winners a place in the playoffs for the first time since 1976.
Urdapilleta scored his team's fourth try and also contributed 22 points with his unerring boot in helping consign Toulouse to a ninth defeat in 10 matches that leaves them rooted in 12th position in the table, above only relegated clubs Grenoble and Bayonne.
The result saw Castres move provisionally up to fourth on 63 points, with their final regulation season match at Brive next weekend decisive for their progress to the season-ending playoffs.
Alex Tulou, for Castres, and ex-All Black Luke McAlister, for Toulouse, each crossed for first-half tries.
But with Urdapilleta chipping away at the scoreboard, the floodgates soon opened in the second-half, Julien Caminati (2), Brice Mach and Julien Dumora all crossing the whitewash in a totally dominant, bonus-point performance by the home side.
Toulouse coach Ugo Mola, who took over from Guy Noves when the latter moved to the France job, said the result summed up a "complicated" season.
"Today we saw the difference between a team that still has something to play for and one which very definitely let go," the former France full-back said.
"Pride has taken a hit. We're closer to shame than anything else."