Biarritz moved to within a point of Saracens at the top of Pool 5 after beating them 15-10 in a Heineken Cup clash in Aquitaine this afternoon.
The French outfit scored two second-half tries through Imanol Harinordoquy Takudzwa Ngwenya to come from behind and claim the victory.
After a scoreless first period which saw both sides miss penalty attempts, Owen Farrell finally gave the Sarries a 52nd minute lead with a successful kick.
However the visitors advantage did not last long, with Harinordoquy crossing just five minutes later before Julien Peyrelongue made up for missing the conversion attempt by scoring a penalty.
Ngwenya then scored a breakaway try, which was successfully converted by Peyrelongue to secure victory for Biarritz.
However the English champions earned what could prove to be a crucial bonus point when Alex Goode went over in the corner late, with Farrell adding the conversion to reduce the losing deficit to just five points.