With only one win in six Premiership games, the English club scored five tries overcoming the tough French side and with home-and-away matches against minnows Calvisano and Dax to come, Stuart Lancaster's men must rate their chances of a berth in the quarter-finals.

Argentinian-born fly-half Alberto Di Bernardo opened the scoring for Leeds with a penalty goal, and scrum-half Joe Bedford bagged the game's first try as the English club won the early exchanges.

Castres' Romain Teulet (two) and Di Bernardo traded penalty goals, before Leeds' Tongan Test hooker Viliami Ma'asi rumbled over to give his side a healthy 16-6 lead on the half-hour mark, and Andy Tuilagi's try immediately after half-time gave Leeds a match-winning lead.

Ma'asi's compatriot Lei Tomiki scored off the back of the scrum to give Castres a sniff at 23-13, but two tries in four minutes from Calum Clark and Tom Biggs gave the home side the win and a try bonus point.

Castres replacement Gerhard Visloo crossed the line as the visitors made a last-ditch effort for a bonus point of their own, but the Leeds defence ensured that the Pool Five finishing order almost certainly depends on the teams' return match in January.