Biarritz held on for a 26-23 victory over London Wasps in Saturday's Amlin Challenge Cup quarter-final at Adams Park.
Dimitri Yachvili broke Wasps' hearts with a late penalty to set up a semi-final at home to the winners of Sunday's clash between Brive or the Scarlets.
The result is the Basques club's fifth consecutive victory in all competitions as they continue a great weekend for French teams after Stade Français and Toulon booked their places in the semi-finals on Thursday and Friday respectively.
Wasps fought back from 23-9 down to level the scores at 23-23 before Yachivili - who produced a 100 per cent kicking display - landed his 75th-minute kick to secure victory in Wycombe.
Former England full-back Iain Balshaw scored the game's first try after Wasps fly-half Nick Robinson, under pressure from USA star Taku Ngwenya, failed to take Yachvili's restart and the Zimbabwe-born winger slipped the ball to Balshaw, who had a clear run to the line.
Yachvili added the conversion to edge Biarritz 7-6 ahead and, five minutes later, increased the lead with a penalty.
Robinson's third penalty cut the deficit to one point with half-time looming, but the French side responded quickly as the dangerous combination of Balshaw and Ngwenya linked up once more in a move which ended with prop Eugene van Staden squeezing in at the right-hand corner
Yachvili landed the difficult conversion from the touchline to give BO a 17-9 lead at the break.
Two more Yachvili second penalties stretched the lead to 23-9 on the hour mark but Wasps' gallant efforts were rewarded with two tries in a three-minute spell.
After 62 minutes Robinson's through kick, deflected off a Biarritz player, bounced into the arms of Christian Wade who marked his return from injury by racing in unchallenged.
Wasps struck again with centre Ryan Davies forcing his way over between the posts. Robinson converted both, and the sides were level at 23-23 but Yachvili's boot would have the final say.
Tries: Wade, Davis
Cons: Robinson 2
Pens: Robinson 3
Tries: Balshaw, van Staden
Cons: Yachvili 2
Pens: Yachvili 4
London Wasps: 15 Hugo Southwell, 14 Richard Haughton, 13 Elliott Daly, 12 Ryan Davis, 11 Christian Wade, 10 Nicky Robinson, 9 Charlie Davies, 8 Sam Jones, 7 Matt Everard, 6 Joe Launchbury, 5 Richard Birkett, 4 James Cannon, 3 Ben Broster, 2 Vladislav Korshunov, 1 Zak Taulafo.
Replacements: 16 Nathan Morris, 17 Tim Payne, 18 Simon McIntyre, 19 Ross Filipo, 20 James Harris, 21 Jack Wallace, 22 Tom Prydie, 23 Tom Lindsay,
Biarritz Olympique: 15 Iain Balshaw, 14 Taku Ngwenya, 13 Charles Gimenez, 12 Dane Haylett-Petty, 11 Benoît Baby, 10 Julien Peyrelongue, 9 Dimitri Yachvili (capt), 8 Raphael Lakafia, 7 Benoit Guyot, 6 Wenceslas Lauret, 5 Pelu Taele, 4 Erik Lund, 3 Eugène Van Staden, 2 Eusebio Guinazu, 1 Yvan Watremez.
Replacements: 16 Romain Terrain, 17 Sylvain Marconnet, 18 Francisco Gomez Kodela, 19 Jean-Baptiste Roidot, 20 Imanol Harinordoquy, 21 Florian Faure, 22 Jean-Pascal Barraque, 23 Marcelo Bosch,
Venue: Adams Park, High Wycombe
Referee: John Lacey