|European Champions Cup: Bordeaux-Begles v Ospreys|
|Bordeaux-Begles (25) 33|
|Tries: Rey, Botha, Guitoune, Lesgourgues Cons: Bernard 2 Pens: Bernard 2, Serin|
|Ospreys (10) 27|
|Tries: Tipuric, Walker, Jones, Biggar Cons: Biggar 2 Pens: Biggar|
Ospreys claimed two bonus points in their defeat against Bordeaux-Begles to keep alive their European Champions Cup quarter-final hopes.
Tries from Julien Rey, Berend Botha and Sofiane Guitoune gave Bordeaux a commanding 25-10 half-time lead.
But Eli Walker, Alun Wyn Jones and Dan Biggar added to Justin Tipuric's first-half score to make it 30-27.
Yann Lesgourgues's try had given Bordeaux a bonus point and Baptiste Serin's penalty made sure of victory.
Ospreys remain top of Pool Two, two points ahead of second-placed Exeter, who visit Clermont Auvergne on Sunday.
The Welsh region were forced into a late change before kick-off in Bordeaux, with fly-half Sam Davies brought in at outside centre to replace the injured Josh Matavesi.
It was a chastening start for the makeshift midfield partnership of Davies and Ben John, as an incisive Bordeaux move allowed centre Rey to bundle his way over.
Ospreys responded swiftly, as Dan Evans and Jeff Hassler combined for Wales flanker Tipuric to run clear for a fine score.
The visitors were given another lift when home hooker Clement Maynadier was yellow-carded for a deliberate knock-on, but it was Bordeaux who scored during his 10 minutes in the sin-bin.
Second row Botha brushed off Scott Baldwin's tackle to touch down in the corner and a second Pierre Bernard penalty put Bordeaux 18-7 ahead.
Wing Guitoune then seized on a loose Davies pass to run the length of the field and cross for the hosts' third try.
That left Ospreys trailing 25-10 at the interval but, 10 minutes after the restart, Walker's simple finish in the corner gave them hope.
A yellow card for Serin boosted the visitors' chances further, but again Ospreys were stung by a counter-attack.
Home wing Metuisela Talebulamaijaina broke out of his own 22, kicked ahead and, with Evans unable to gather on the Ospreys' try line, Lesgourgues was on hand to touch down.
Ospreys were determined to salvage something from the game and captain Jones set up a tense finale as he crashed over for his side's third try.
Biggar then intercepted a pass near his own 22 and scampered clear to score Ospreys' bonus point-securing fourth try and cut Bordeaux's lead to 30-27.
But with the final kick of the game, Serin struck a penalty to seal Bordeaux's first European win of the season.
Ospreys backs coach Gruff Rees told BBC Radio Wales: "We're disappointed. Bordeaux are a powerful outfit but I don't think they worked for their scores.
"A couple of them came from our inaccuracies when we've been trying to create some pressure of our own.
"We are too loose and we don't create sustained pressure. For all the good in our game, and there are positives, we feel we've allowed their big runners to get momentum and conceded cheap tries."
Bordeaux-Begles: Jean-Marcellin Buttin; Metuisela Talebulamaijaina, Adam Ashley-Cooper, Julien Rey, Sofiane Guitoune; Pierre Bernard, Heini Adams; Jefferson Poirot, Clement Maynadier, Sekope Kepu, Julien Le Devedec, Berend Botha, Louis Madaule, Matthew Clarkin (capt), Marco Tauleigne.
Replacments: Ole Avei, Steven Kitshoff, Francisco Gomez Kodela, Jan Andre Marais, Loann Goujon, Yann Lesgourgues, Baptiste Serin, Darly Domvo.
Ospreys: Dan Evans; Jeff Hassler, Sam Davies, Ben John, Eli Walker; Dan Biggar, Tom Habberfield; Paul James, Scott Baldwin, Dmitri Arhip, Lloyd Ashley, Alun Wyn Jones (capt), Dan Lydiate, Justin Tipuric, James King.
Replacements: Sam Parry, Ryan Bevington, Aaron Jarvis, Rory Thornton, Olly Cracknell, Dan Baker, Martin Roberts, Hanno Dirksen.
Referee: Luke Pearce (England).
Touch judges: Matthew Carley (England), Peter Allan (England).
TMO: Rowan Kitt (England).
Citing commissioner: John Cole (Ireland).