Wasps slipped out of the Heineken Cup after a 21-15 defeat at Castres.

The two-time European champions had to win in the south of France to keep alive their hopes of progressing to the quarter-finals - and looked to be on course when Dominic Waldouck handed them the lead 13 minutes from time.

But a host of missed chances before a second try for Thomas Bouquie handed Castres their second win of the campaign, ending Wasps' interest in this season's tournament.

Castres had little more to play for than pride in front of a modest home crowd following four defeats from their five previous pool games.

However, the hosts drew first blood through Bouquie in the 14th minute.

The full-back dummied a pass and stepped through the Wasps line before racing clear from 15 metres out for an impressive solo try which was converted by Romain Teulet.

Danny Cipriani registered Wasps' first points on the board in the 18th minute with a penalty but that was only a brief respite as Castres stepped up the pressure with prop Luc Ducalcon going close, held up over the line.

Number eight Iosefa Tekori charged from the ensuing scrum before slipping a clever pass inside to Chris Masoe, who crashed over to the left of the posts. Teulet swept home the conversion to open a 14-3 lead after 23 minutes.

Wasps were facing the Heineken Cup exit door but were offered a route back through a remarkable solo score by England outside-half Cipriani which reduced the deficit to 14-10 before half-time.

Cipriani darted to the right of a ruck 10 metres inside the Castres half, stepped past Masoe and wing Rafael Carballo before streaking clear to touch down under the posts to make his conversion a formality.

Teulet missed the chance to re-establish a seven-point lead when he struck the post with a penalty after Wasps were turned over in midfield.

However the Guinness Premiership side were guilty of wasting chances as well when Rob Webber failed to gather Paul Sackey's inside pass with the try line at his mercy, before Cipriani pushed a 61st-minute penalty to the right of the posts.

Castres thought they had put the tie out of reach when hooker Akvsenti Giorgadze was judged to have been held up over the try line following a length-of-the-field attack.

Steven Kefu and Tekori again provided the cutting edge for Castres, replacements Romain Terrain and Fabio Staibano offering fresh legs but Joe Worsley and George Skirvington combined to keep the hooker at bay.

Wasps capitalised on the decision after James Haskell's covering tackle cleared the danger from the resulting scrum.

Mark van Gisbergen led the breakout, Tim Payne and Richard Birkett kept the attack alive before Riki Flutey released Waldouck - who handed off with ease before stepping past Carballo to give Wasps the lead for the first time after 67 minutes.

Waldouck made way for Tom Voyce after injuring himself in the process and Cipriani missed the chance to stretch the one-point lead when he was off the mark with the conversion.

That lead remained intact when Bouquie was also off-target with an ambitious long-range penalty for Castres as the game edged into the final minutes - but again Wasps spurned chances.

Van Gisbergen knocked on after Dave Walder broke through, as Wasps chased the bonus point needed to overtake the Ospreys for a place in the last eight.

That miss came back to haunt them when Castres stole victory four minutes from time with Bouquie's second score.

Again man of the match Tekori was involved before Castres stretched Wasps out wide, releasing the full-back who passed outside Walder and inside Van Gisbergen with ease to settle the tie.

Teulet converted to send Wasps crashing out.