Biarritz saw their Heineken Cup campaign hit a major speedbump as they fell 30-26 to Treviso at Stadio Comunale di Monigo on Saturday.
The game was nip and tuck in the opening stages but exploded to life after fifteen minutes, when Treviso crossed for two quick-fire tries.
First, Michele Rizzo barged over from short range for a try that was converted by Tobias Botes before Robert Barbieri struck for a second score, this time converted by Chris Burton.
Biarritz hit back within ten minutes with an unconverted try when Pelu Taele-Pvihi powered his way over the try-line after his team-mates had rallied following the early setback.
But the hosts struck again shortly after, with Italian international Cornelius van Zyl touching down after great work by the Treviso pack in midfield. The try was converted, making it 21-5 in favour of the hosts, but Marcelo Bosch's converted try before the interval helped keep Biarritz in touch, before Burton booted a over a penalty for Treviso on the stroke of half-time.
Burton was on target in the opening stages of the second half to make it 27-12, but the majoriy of the remainder of the half was dominated by Biarritz, who desperately searched for a way back in the game.
They gave themselves a lifeline when Damien Trialle crossed just before the hour mark and were only a point behind when Yan Lesgourgues scored minutes later to ensure a bonus.
The closing stages of the match were tense, but it was Treviso who were able to hold on for a fantastic win, with a Burton penalty on 77 minutes round things off.
Tries: Rizzo, Barbieri, van Zyl
Con: Botes, Burton 2
Pen: Burton 3
Tries: Taele, Bosch, Traille, Lesgourgues
Con: Baby, Peyrelongue 2
Treviso: 15 Luke McLean, 14 Ludovico Nitoglia, 13 Tommaso Benvenuti, 12 Alberto Sgarbi, 11 Brendan Williams, 10 Kristopher Burton, 9 Tobias Botes, 8 Paul Derbyshire, 7 Alessandro Zanni, 6 Robert Barbieri, 5 Cornelius van Zyl, 4 Antonio Pavanello, 3 Lorenzo Cittadini, 2 Enrico Ceccato, 1 Michele Rizzo.
Replacements: 16 Diego Vidal, 17 Ignacio Fernandez Rouyet, 18 Pedro di Santo, 19 Valerio Bernabo, 20 Manoa Vosawai, 21 Marco Filippucci, 22 Edoardo Gori, 23 Alberto Di Bernardo.
Biarritz: 15 Iain Balshaw, 14 Taku Ngwenya, 13 Benoît Baby, 12 Damien Traille, 11 Ilikena Bolakoro, 10 Marcelo Bosch, 9 Yann Lesgourgues, 8 Florian Faure, 7 Talalelei Gray, 6 Wenceslas Lauret, 5 Pelu Taele, 4 Jérôme Thion, 3 Campbell Johnstone, 2 Benoit August, 1 Fabien Barcella.
Replacements: 16 Romain Terrain, 17 Yvan Watremez, 18 Sylvain Marconnet, 19 Jean-Baptiste Roidot, 20 Benoit Guyot, 21 Julien Peyrelongue, 22 Charles Gimenez, 23 Dane Haylett-Petty.
Referee: JP Doyle (England)
Assessor: Tim Aplin (Ireland)