Ospreys made heavy weather of their 19-16 victory over a Bordeaux-Bègles side that had 14 men for much of the second-half.
UBB's Felix le Bourhis scored a well-worked try, however it was cancelled out by the man that scored all of Ospreys’ points Dan Biggar.
Prior to the red card, which Jean-Baptiste Dubié received for using a swinging arm in a tackle on Biggar, it was a game that could have gone either way, however Ospreys take the advantage into the second leg of the back-to-back fixtures.
In the opening five minutes Biggar and Pierre Bernard exchanged early penalties as both sides settled into the game.
Ospreys spoiled two early try-scoring opportunities as Daniel Evans fumbled a final pass out wide and Brendon Leonard’s quick tap didn’t pay off as he was penalised for holding on.
With a quarter gone Biggar added another three, it could have been more after he intercepted Bernard’s inside pass, however UBB backtracked well before infringing at the breakdown.
The visitors were winning the collisions and their pressure was rewarded with a long-range penalty from their Bernard’s boot.
On the half-hour mark Bordeaux-Bègles had their tails up and their pack rumbled a driving maul 20 metres up the field.
The result was a five-metre lineout, Alun Wyn Jones receiving a yellow card and then Le Bourhis exploiting the space to deliver the first try of the game.
With half time in sight Biggar stepped up and reduced the deficit however at 9-13 down the Ospreys had a spot of work to do at the break.
Immediately after half-time the home sides’ pack dominated the opening scrum and Biggar added three more to his tally.
Shortly after the fly-half took a clattering from Dubié. Referee JP Doyle reviewed the incident and gave the French winger his marching orders.
With the numerical advantage the Ospreys pressed quickly and exploited the extra space with the Welsh International adding a full five-points and converting his own try.
Heading into the final quarter Bordeaux-Bègles were not in the mood to give up and played with ambition and heart.
Fresh onto the field Romain Lonca narrowed the scores off the tee and could have levelled the game however his second attempt veered off course.
Ospreys were struggling to get their hands on the ball for any great period of time and when they did made basic errors, much their own frustration.
Bordeaux-Bègles threw everything that they could at the home side however ultimately didn’t have enough to take the victory and the Ospreys collectively gave a sigh of relief at full-time.
Pens: Biggar 4
Yellow Card: Jones
Try: Le Bourhis
Pens: Bernard 2, Lonca
Red Card: Dubié
Ospreys: 15 Dan Evans, 14 Hanno Dirksen, 13 Jonathan Spratt, 12 Josh Matavesi, 11 Eli Walker, 10 Dan Biggar, 9 Brendon Leonard, 8 James King, 7 Justin Tipuric, 6 Dan Lydiate, 5 Alun Wyn Jones (c), 4 Lloyd Ashley, 3 Dmitri Arhip, 2 Scott Baldwin, 1 Paul James.
Replacements: 16 Sam Parry, 17 Nicky Smith, 18 Aaron Jarvis, 19 Rory Thornton, 20 Dan Baker, 21 Tom Habberfield, 22 Sam Davies, 23 Ben John.
Bordeaux-Bègles: 15 Jean-Marcellin Buttin, 14 Jean-Baptiste Dubié, 13 Felix Le Bourhis, 12 Charles Brousse, 11 Nans Ducuing, 10 Pierre Bernard, 9 Heini Adams, 8 Marco Tauleigne, 7 Hugh Chalmers, 6 Matthew Clarkin, 5 Adam Jaulhac, 4 Berend Botha, 3 Sekope Kepu, 2 Clement Maynadier, 1 Jefferson Poirot.
Replacements: 16 Ronan Chambord, 17 Jean-Baptiste Poux, 18 Patrick Toetu, 19 Cyril Cazeaux, 20 Louis Madaule, 21 Baptiste Serin, 22 Romain Lonca, 23 Paulin Riva.
Referee: JP Doyle (England)
Assistant Referees: Greg Garner (England), Paul Burton (England)
TMO: Sean Davey (England)