Racing Metro recorded a dogged 15-3 win over Edinburgh on Friday to keep their European Cup quarterfinal hopes alive.
In a battle of the boot at Murrayfield, Olly Barkley and Gaeton Germain kicked penalties inside the first seven minutes with Piers Francis cutting the French side's lead after 27 minutes.
But the former Waikato Chiefs flyhalf was guilty of five misses out of six attempts on a rain-swept night while Germain was successful with three second half penalties.
The win took Racing to the top of Pool One ahead of Sunday's match between Saracens and Munster.
Torrential rain reduced the Stade Aguilera pitch in Biarritz to a virtual swimming pool as the French side set about avenging their shock 22-14 defeat to Connacht in Ireland last weekend.
Dmitri Yachvili kicked a third-minute penalty before his team had a try ruled out when Takudzwa Ngwenya aquaplaned into touch before he was able to ground the ball.
However, Biarritz grabbed a deserved lead on the half hour when Iain Balshaw darted between a gap left wide open by Dan Parks to score with Yachvili succeeding with a tricky conversion from the touchline for a 10-0 lead at the interval.
The pitch got increasingly heavier in the second half ruining the game as a spectacle.
Fijian replacement Seremaia Burotu grabbed a last-minute try, converted by Yachvili, to give Biarritz a 17-0 victory.
But Biarritz remain five points behind Pool Four leaders Ulster, who are at home to Northampton on Saturday.
Edinburgh 3-15 Racing Metro
For Racing Métro:
Pens: Barkley, Germain 4
Edinburgh: 15 Greig Tonks, 14 Lee Jones, 13 Ben Cairns, 12 Ben Atiga, 11 Dougie Fife, 10 Piers Francis, 9 Chris Leck, 8 Netani Talei, 7 Roddy Grant, 6 Stuart McInally, 5 Grant Gilchrist, 4 Robert McAlpine, 3 Geoff Cross, 2 Ross Ford, 1 John Yapp.
Replacements: 16 Andy Titterrell, 17 Allan Jacobsen, 18 Willem Nel, 19 Perry Parker, 20 Dimitri Basilaia, 21 Richie Rees, 22 Gregor Hunter, 23 Sep Visser.
Racing Métro: 15 Gaetan Germain, 14 Sereli Bobo, 13 Guillaume Bousses, 12 Alexandre Dumoulin, 11 Juan Imhoff, 10 Olly Barkley, 9 Sebastien Descons, 8 Jacques Cronje, 7 Bernard Le Roux, 6 Antoine Batut, 5 Francois van der Merwe, 4 Karim Ghezal, 3 Luc Ducalcon, 2 Dimitri Szarzewski, 1 Eddy Ben Arous.
Replacements: 16 Thomas Bianchin, 17 Julien Brugnaut, 18 Juan Pablo Orlandi, 19 Jone Qovu Nailiko, 20 Mathieu Belie, 21 Juan Martin Hernandez, 22 Fabrice Estebanez, 23 Alvaro Galindo.
Biarritz 17-0 Connacht
Tries: Balshaw, Burotu
Cons: Yachvili 2
Biarritz: 15 Iain Balshaw, 14 Taku Ngwenya, 13 Jean-Pascal Barraque, 12 Damien Traille, 11 Aled Brew, 10 Julien Peyrelongue, 9 Dimitri Yachvili, 8 Imanol Harinordoquy (captain), 7 Raphael Lakafia, 6 Wenceslas Lauret, 5 Pelu Taele, 4 Erik Lund, 3 Francisco Gomez Kodela, 2 Benoit August, 1 Fabien Barcella.
Replacements: 16 Jean-Philippe Genevois, 17 Lodewicus Blaauw, 18 Thomas Synaeghe, 19 Thibault Dubarry, 20 Magnus Lundy, 21 Yann Lesgourgues, 22 Seremaïa Burotu, 23 Marcelo Bosch.
Connacht: 15 Robbie Henshaw, 14 Tiernan O'Halloran, 13 Danie Poolman, 12 Dave McSharry, 11 Fetu'u Vainikolo, 10 Dan Parks, 9 Kieran Marmion, 8 Eoin McKeon, 7 Johnny O'Connor, 6 Andrew Browne, 5 Mike McCarthy, 4 Mick Kearney, 3 Ronan Loughney, 2 Jason Harris Wright, 1 Brett Wilkinson.
Replacements: 16 Ethienne Reynecke, 17 Dennis Buckley, 18 JP Cooney, 19 Danny Qualter, 20 George Naoupu, 21 Paul O'Donohoe, 22 Miah Nikora, 23 Matthew Jarvis.