Castres edged into the Heineken Cup semi-finals, beating hot favourites Montferrand to inflict the second successive defeat on last season's French championship finalists.

Castres scored the only try of the match through former Stade Francais back row forward Romain Froment while kicker Romain Teulet slotted 14 points.

Montferrand's French international fly-half Gerald Merceron scored all his team's points.

However, Montferrand could have stolen victory in injury-time but for a handling error by winger Aurelien Rougerie.

The French international was set free by Merceron but knocked the ball on yards from the line - a mistake which was, sadly, reflective of a scrappy match.

The greatest cheer of the day came when Castres' Ivory Coast forward Ismael Lassissi came on as a second-half replacement.

Lassissi's return came one day after he had his year-long suspension for allegedly biting Munster prop Peter Clohessy a fortnight ago rescinded.