|Ospreys (9) 19|
|Tries: Biggar Cons: Biggar Pens: Biggar 4|
|Bordeaux-Begles (13) 16|
|Tries: Le Bourhis Cons: Bernard Pens: Bernard 2, Lonca|
Dan Biggar scored all 19 points as Ospreys maintained their lead at the top of Pool 2 in the European Champions Cup with a hard-fought win over 14-man Bordeaux-Begles.
Bordeaux led at the interval through Felix Le Bourhis' try but Biggar's three penalties kept Ospreys in touch.
Jean-Baptiste Dubie was sent off for a high tackle on Biggar, whose converted try put Ospreys ahead.
The French side never gave up and secured a losing bonus point.
Bordeaux made 13 changes from the side that had beaten Stade Francais the previous week while Alun Wyn Jones, Dan Lydiate, Biggar and Scott Baldwin retuned to the Ospreys line-up.
Biggar gave the Ospreys an early lead with a penalty from in front of the posts, but Pierre Bernard succeeded with a kick of his own to level two minutes later.
Both sides showed intent to move the ball during the opening period with Biggar intercepting opposite number Bernard's pass, but did not have the pace or support to threaten the try line.
The Wales fly-half restored the home side's lead with his second penalty of the game but Bernard's second kick brought Bordeaux level.
Ospreys were reduced to 14 men when captain Jones was shown a yellow card for dragging down a driving line-out as the visitors pressed.
Bordeaux-Begles took full advantage of Jones' absence when, following a rolling maul, Felix Le Bourhis scored on the overlap to cross for the opening try.
Bernard added the conversion, although Biggar's third penalty reduced the deficit to four points before the interval.
Ospreys reduced the gap to a single point two minutes into the second half with Biggar maintaining his 100% kicking record with a fourth penalty.
Biggar was on the receiving end of a late high tackle from Dubie, who was sent-off following a TMO review.
Reduced to 14 men, Bordeaux-Begles were further punished when Brendon Leonard sent Biggar over to cross in the corner before converting the try.
Despite their numerical disadvantage the visitors dominated the next 10 minutes and came within inches of the Ospreys try line, but the home side's defence stood firm.
Romain Lonca replaced Bernard and his first contribution was a successful penalty, however a second kick - which would have levelled the scores - went wide.
The second half did not reach the levels of the opening 40 minutes and Bordeaux finished the game with 13 men after prop Jean-Baptiste Poux was given a yellow card.
The sides meet again in the return match in France on Saturday, 19 December.
Ospreys forwards coach Chris Gibbes told BBC Radio Wales:
"Happy to get the result but the performance was below-par. We got caught out in a few areas around the line-out and it cost us.
"A lot of respect has got to be paid to them. They were down to 14 men and they didn't change and they kept coming at us and really put us under pressure.
"It's going to a tough place to go next week but we believe we can do it."
Ospreys: Dan Evans; Hanno Dirksen, Jonathan Spratt, Josh Matavesi, Eli Walker; Dan Biggar, Brendon Leonard; Paul James, Scott Baldwin, Dmitri Arhip, Lloyd Ashley, Alun Wyn Jones (capt), Dan Lydiate, Justin Tipuric, James King.
Replacements: Sam Parry, Nicky Smith, Aaron Jarvis, Rory Thornton, Dan Baker, Tom Habberfield, Sam Davies, Ben John.
Bordeaux-Begles: Jean-Marcellin Buttin; Jean-Baptiste Dubie, Felix Le Bourhis, Charles Brousse, Nans Ducuing; Pierre Bernard, Heini Adams; Jefferson Poirot, Clement Maynadier, Sekope Kepu, Berend Botha, Adam Jaulhac, Matthew Clarkin (capt), Hugh Chalmers, Marco Tauleigne.
Replacements: Ronan Chambord, Jean-Baptiste Poux, Patrick Toetu, Cyril Cazeaux, Louis Madaule, Baptiste Serin, Romain Lonca, Paulin Riva.
Referee: JP Doyle (England)
Touch judges: Greg Garner, Paul Burton (England)
TMO: Sean Davey (England)
Citing commissioner: Gordon Black (Ireland)