Leeds Carnegie went into their final European Pool game against French side Castres Olympique looking to secure their place at the top of the table, but terrible weather at the Stade Pierre Antoine made this a difficult task with both sides forced into battle on a virtual mudbath.  The torrential rain meant that both teams' efforts to control the ball were near impossible, but in the end it was Castres who proved they were able to handle the conditions better, finishing the game as 13-3 victors to deny Leeds the top spot and a losing bonus point.
This now means that Leeds Carnegie are in for a nervous wait to see whether or not they will qualify for the quarter finals as one of the three best runners up.  All eyes will now be on the result between Bath and Auch, with Auch needing a massive win at the Recreation Ground to overturn a 78 point deficit to secure their place in the next round.
The conditions meant that neither of the teams were able to put together any flowing rugby and both resorted to kicking high balls to create opportunities in the first half.  Castres had a chance to take the lead on 15 minutes when they were awarded a penalty but Romain Teulet put his kick just wide to keep the game scoreless. 
As the match progressed, the Castres pitch became a quagmire and the players were almost unrecognisable, with an extra layer of mud covering them from head to toe.  The visitors dug in though and had the majority of possession throughout the first half.
To their credit when Castres did get the ball they attempted to play a passing game, but the heavy rain made this a futile mission and with Leeds putting in a strong defensive performance their efforts went unrewarded.  On 30 minutes Castres had their best attacking opportunity when a neat chip on the halfway line found Steve Kefu who combined with captain Lionel Nallet to move towards the tryline, but once again the Leeds Carnegie forwards ensured the French side was denied.
As the first half drew to a close Leeds looked determined to get points on the score board but despite lots of driving play, in particular from Vili Ma'asi, who had a superb first half, they were unable to break through and the score remained 0-0 at half time.
In the second half Castres came out pumped up and had created most of the chances in the opening 10 minutes, but despite being camped in the Leeds half for most of the opening period they were unable to find their way over the try line.
Stuart Lancaster brought on fresh blood after 10 minutes to help boost his troops but on 58 minutes Castres finally broke the deadlock with Teulet kicking a penalty from just in front of the posts. 
Just five minutes later Leeds Carnegie found themselves further behind when Castres converted their second penalty to put them 6-0 in front.    From here the home side seemed to step up a gear and continued to build momentum and on 66 minutes Leeds were dealt a further blow when centre Andy Tuilagi was sin binned for foul play after the whistle.  With the extra man Castres were able to take advantage and on 70 minutes Argentine international Rafael Carbello scored his fourth try of the competition, when he drove his way over from a metre out to touch the ball down under the posts.  Teulet added the conversion to widen the gap to 13-0.
Leeds Carnegie were given a lifeline with two minutes to go when they were awarded a penalty, which Alberto Di Bernardo slotted over to bring the score to 13-3.  Leeds then began to show some urgency and as the clock ticked down they tried to push forward in search of the try they needed to ensure they at least took a point away from the game. 
Di Bernardo had the chance to narrow the deficit by a further three points when Leeds were awarded a second penalty in injury time, but it was not to be and this time the fly half put his kick wide in difficult conditions.  This proved to be the last chance for the visitors, with the final score ending 13-3 to Castres.

Castres Olympique: Carl Hoeft, Romian Terrain, Daniel Saayman, Tim Barker, Lionel Nallet (c), Joe Tekori, Alexandre Bias, Florian Faure, Romian Teulet, Pablo Canavosio, Steve Kefu, Phil Christophers, Rafael Carballo, Cameron McIntyre, Kevin Senio.   Subs: Akvensti Giorgadze, Kees Meeuws, Rodrigo Capo Ortega, Lei Tomiki, Sebastien Tilous Borde, Anthony Lagarere, Lionel Mazars

Leeds Carnegie: Mike MacDonald, Vili Ma'asi, Tom McGee, Erik Lund, Pablo Bouza, Danny Paul, Martin Schusterman, Rhys Oakley, Jonny Hepworth, Leigh Hinton, Rob Vickerman, Lee Blackett, Tom Biggs, Alberto Di Bernardo, Joe Bedford (c).  Replacements: James Parkes, Adam Hopcroft, Fosi Pala'amo, Calum Clark, Mike Aspinall, Apo Satala, Andy Tuilagi