The Cardiff Blues salvaged a losing bonus point at Castres thanks to a last-minute try by Scott Andrews. The Welsh region looked set to leave Stade Pierre Antoine empty-handed as they trailed 27-13 with the full-time whistle approaching. But the replacement prop barged over from close range for a try that was converted by Ceri Sweeney to clinch the consolation point.
The Blues captain, Xavier Rush, said: "This is a very tight pool where you have to take whatever you can get on the road and as the competition develops that bonus point could prove crucial.
"We weren't surprised by the way Castres came at us. They have a very proud record at home in the French league and have not been beaten here for some time. We knew they would come at us but unfortunately it took us a long time to get into the game.
"They were better than us in most areas in the first half. We struggled at the scrum and what ball we did have we turned over. We made them look pretty good."
Castres had stormed into a 27-6 half-time lead, thanks to quick-fire tries from their wings, Vincent Inigo and Marc Andreu. The Tongan back-rower Ma'ama Molitika sparked a second-half Blues recovery with a try.
The Blues' coach, Dai Young, would have left France satisfied with the bonus point, given the way that his team were steamrollered in the first half. Castres were on the front foot from the start and they opened the scoring with a Romain Teulet penalty. The full-back kicked another two penalties either side of a Seremaia Bai drop goal before Ben Blair kicked the Blues' first points.
The full-backs exchanged penalties to bring the score to 15-6 before, after 36 minutes, Inigo danced through the visitors' defence. The wing pounced on a speculative Yoan Audrin kick and skipped past Leigh Halfpenny to score. Teulet converted for a 22-6 lead.
Minutes later Audrin burst down the wing. The ball was spread to Teulet, who chipped to the corner for Andreu to score.
The Blues played with increased intensity after the break and they got their first reward six minutes into the half when Molitika crashed over. The Wales centre Tom Shanklin gathered his own grubber kick and passed inside to Chris Czekaj, who fed inside to the substitute Tom James. James was tackled high but was able to recycle the ball, which Richie Rees popped to Molitika, who drove through two defenders to score. Sweeney converted for 27-13.
The Blues threatened to score on several occasions before Thomas Sanchou was sent to the sin-bin for killing the ball. After a quick tap and several phases, Andrews drove through, with the help of Sam Warburton, to score the valuable try.
Castres Olympique Teulet; Inigo, Audrin, Baikeinuku, Andreu (Bernard, 73); McIntyre, Tillous-Borde (Sanchou, 73); Forestier, Kayser (Bonello, 54), Ducalcon (Saayman, 72), Tekori, Rolland, Diarra, Caballero (Murray, 73), Masoe (capt; Bornman, 59).
Tries Inigo, Andreu Con Teulet Pens Teulet 4 Drop goal Bai.
Sin-bin Sanchou 79.
Cardiff Blues Blair (James, 42); Halfpenny, Laulala, Shanklin, Czekaj; Sweeney, Rees; Jenkins, Thomas (R Williams, 28), Filise, B Davies, Jones (Tito, 69), Molitika (Pretorius, 69), Warburton, Rush (capt).
Referee Alan Lewis (Ireland) Attendance 8,954.
