Biarritz were made to work hard for a 19-11 victory over Italian side Viadana in their opening Heineken Cup pool four fixture on Saturday.
The 2006 finalists trailed 8-6 just before half-time following Steven Bortolussi's try but Ashwin Willemse scored his side's only try seconds before the interval.
Dimitri Yachvili converted to make it 13-8 and added two more penalties in the second half.
Viadana, back in the competition after six years and seeking their first ever victory, could only muster a second Corrado Pilat penalty in reply.
Pens: Pilat 2
Pens: Yachvili 4
Viadana: 15 Hayden Reid, 14 Steven Bortolussi, 13 Roberto Talotti, 12 Garry Law, 11 Hayden Pedersen, 10 Corrado Pilat, 9 Craig McGrath, 8 Josh Sole (capt), 7 Aldo Birchall, 6 Sam Harding, 5 Quintin Geldenhuys, 4 Cristian Bezzi, 3 Ignacio Rouyetl, 2 Luigi Ferraro, 1 Miguel Alonso.
Replacements: 16 Plinio Sciamanna, 17 Andrea Moretti, 18 Luca Redolfini, 19 Dion Waller, 20 Samuele Pace, 21 Jaco Erasmus, 22 Calvin Howarth.
Biarritz: 15 Nicolas Brusque, 14 Ashwin Willemse, 13 Henry Fa'afili, 12 Damien Traille, 11 Jean-Baptiste Gobelet, 10 Julien Peyrelongue, 9 Dimitri Yachvili, 8 Jacques Cronje, 7 Imanol Harinordoquy, 6 Samiu Vahafolau, 5 Santiago Dellapè, 4 Jérôme Thion, 3 Denis Avril, 2 Benoît August (c), 1 Eduard Coetzee.
Replacements: 16 Benjamin Noirot, 17 Benoît Lecouls, 18 Manuel Carizza, 19 Mohamed Dridi, 20 Fabien Cibray, 21 Marcelo Bosch, 22 Andrea Masi.
Referee: Peter Allan (Scotland)