Biarritz set up an Amlin Challenge Cup final against Toulon with a 19-0 home win against Brive.
The home side triumphed through a Damien Traille try and 14 points from the boot of Dimitri Yachvili after leading 13-0 at half-time.
Jonny Wilkinson slotted a last-gasp drop-goal to book Toulon's spot with a 32-29 win against Stade Francais.
The former England fly-half scored 27 points in a thriller which saw Stade Francais lead 19-11 at half-time.
The final will take place at Twickenham's Stoop on Friday 18 May.