Perpignan compounded Biarritz's Top 14 relegation worries on Friday with a hard-fought 25-6 victory at Stade Aimé Giral.
Scrum-half Kevin Boulogne scored 22 points - including two tries - as Perpignan secured a crucial win to put a little breathing distance between themselves and the relegation zone.
Boulogne landed the first three of his four penalties to give USAP a 9-0 lead after half-an-hour but his opposite number Jean-Pascal Barraque replied with two place kicks at the end of the first half as the Basques came back strongly.
The second half belonged entirely to the hosts however as Biarritz were unable to match the Catalan's intensity.
Fly-half Gavin Hume added a drop goal before Boulogne touched down twice in the space of six minute around the hour-mark to put USAP beyond reach.
The result sees Perpignan climb up to tenth place while Biarritz sink deeper into the relegation quagmire.
Tries: Boulogne 2
Pens: Boulogne 4
Pens: Barraque 2
Yellow cards: Gomez Kodela (Biarritz 57th min); Taofifenua (Perpignan - 72nd min)
Perpignan: 15 Joffrey Michel, 14 Farid Sid, 13 David Marty, 12 Rudi Coetzee, 11 Adrien Plante,10 Gavin Hume, 9 Kevin Boulogne, 8 Henry Tuilagi, 7 Jean-Pierre Perez, 6 Gregory le Corvec, 5 Robins Tchale-Watchou, 4 Olivier Olibeau, 3 Nicolas Mas, 2 Marius Tincu, 1 Perry Freshwater.
Replacements: 16 Guilhem Guirado, 17 Jerome Schuster, 18 Romain Taofifenua, 19 Damien Chouly, 20 Florian Cazenave, 21 Maxime Mermoz, 22 Nicolas Laharrague, 23 Danie Thiart.
Biarritz: 15 Iain Balshaw, 14 Taku Ngwenya, 13 Jean Pascal Barraque, 12 Seremaia Burotu, 11Dane Haylett-Petty, 10 Damien Traille, 9 Yann Lesgourgues, 8 Imanol Harinordoquy, 7 Talalelei Gray, 6 Wenceslas Lauret, 5 Pelu Taele-Pavihi, 4 Jerome Thion, 3 Francisco Gomez Kodela, 2 Benoit August, 1 Sylvain Marconnet.
Replacements: 16 Arnaud Heguy, 17 Fabien Barcella, 18 Manuel Carizza, 19 Raphael Lakafia, 20 Benoit Guyot, 21 Benoit Baby, 22 Ilikena Bolakoro, 23 Campbell Johnstone.