England inside centre Mike Catt put in a stirring display to keep Bath's Heineken Cup hopes alive.

Playing at fly-half, he dominated the match to issue national manager Clive Woodward with a telling reminder of his skills ahead of the Six Nations.

Catt inspired the visitors to a five-try victory at the Stade Pierre Antoine, crossing for two tries himself.

Despite the wet conditions, Bath's backline sizzled from the kick-off.

They allowed Gregor Townsend to kick a penalty to narrow the gap and then Irish lock Jeremy Davidson drove over from a lineout.

Townsend added two more kicks to put the hosts well in front, but Catt instigated Bath's reply.

He cut through from 45 metres out, leaving defenders for dead as he crossed for his second try.

Castres' 14-10 half-time lead was wiped out just 27 seconds after the interval and Bath's pace created a try on the left from teenage winger Tom Voyce.

However, Bath's fourth try fell to veteran second row Martin Haag, celebrating his 300th appearance in grand style with a try from a well-worked lineout move after 65 minutes.

Perry's conversion and a penalty put Bath 11 points clear and Garteh cooper's try was the icing on the cake.

An injury-time by Guillaume Delmotte was no real consolation for Castres.

Head coach Jon Callard said: "Considering the conditions it was a monumental performance.

"We were a bit immature at times but five tries away from home was magnificent."

Castres: Plisson, Sarramea, Artiguste, Delmotte, Garrigues, Townsend, Seguier, Reggiardo, R. Vigneaux, Tsabadze, Laluque, Davidson, Taussac, Labrousse, Lassissi. Replacements: Batut, Bemazet, Bonorino, Chinaro, Diaz, Denechaud, Albouy.

Bath: Perry, Balshaw, Maggs, Berne, Voyce, Catt, Cooper, Emms, Regan, Mallett, Haag, Borthwick, G. Thomas, Lyle, Clarke. Replacements: Preston, Long, Barnes, A. Adebayo, Thirlby, N. Thomas, Lloyd.

Referee: S De Santis (Italy)