The Scarlets have been beset by a tragic catalogue of near-misses and miss-fortune during the history of the Heineken Cup that has denied them the one trophy that has eluded them.
But Gareth Jenkins and the passionate home crowd can have little argument over the outcome of this quarter-final after losing out to a side far more adept at taking their chances.
Stephen Jones' try closed the gap to 15-10 at set up a thrilling climax but as Llanelli rallied they failed to make the most of their opportunities, Mark Taylor squandering two guilt-edged chances in particular, before Biarritz broke free in the closing stages.
"We're hugely disappointed but I think we have to accept that we were beaten by a better side," said coach Jenkins.
"At this level of rugby it's all about making the most of the opportunities that come along and that was the difference between us.
"They created three half-chances and took them superbly, we created two excellent chances and didn't. At the end of the day that's what counts."
The scoreline was somewhat harsh on Llanelli who were hit late on by tries from Nicolas Brusque and Phillipe Bernat-Salles in the final three minutes. But by then the chance had gone.
Even at this fiercely passionate ground, Biarritz made a mockery of the miss-belief that French sides do not travel well and it was Llanelli, even at 5-3 down, who went into the break the more satisfied having spent almost the entire half pinned on the back foot.
A game of brimming with intensity and fervour ensured scoring chances were at a premium after Jones and Yachvili missed early shots at goal and it was not until the 39th minute that the deadlock was finally broken.
Despite facing an all international pack the French had possessed the greater muscle power up front and it was that, combined with sheer bloody mindedness that edged them over.
David Couzinet's burst set up camp Biarritz's camp at the foot of the Llanelli line from where they launched a series of surges from the base of the scrum. Three times they went over the line, twice denied by the video referee, before Couzinet peeled off yet another drive to score at the fourth attempt.
A Jones penalty after a frantic period, that also saw Serge Betsen yellow carded for kicking, gave Llanelli hope just before the break but that was soon wiped away when Brusque stretched over on 47 minutes.
The arrival of Leigh Davies galvanised the Scarlets attack and set up Jones' try but it was a brief highlight in a frustrating night for the Scarlets.
Llanelli Scarlets 10-27 Biarritz Olympique
Llanelli Scarlets: Try - S Jones; Pen - S Jones; Con - S Jones
Biarritz Olympique: Tries - D Couzinet, N Brusque 2, P Bernat-Salles; DG - J Peyrelongue; Cons - D Yachvili 2.
Heineken man of the match: David Couzinet (Biarritz)
Llanelli Scarlets: B Davies; G Evans, M Taylor, M Watkins, S Finau; S Jones, D Peel; I Thomas, R McBryde, J Davies, V Cooper (capt), C Wyatt, D Jones, S Easterby, S Quinnell
Replacements: J Thiel, A Gravelle, A Jones, D Hodges, M Phillips, G Bowen, L Davies
Biarritz Olympique: N Brusque; P Bidabe, M Gaitan, J Isaac, J Marlu; J Peyrelongue, D Yachvili; P Balan, J Gonzalez, D Avril, H Manent, D Couzinet, S Betsen, O Tonita, T Lievremont (capt)
Replacements: J Campo, M Fitzgerald, S Puleoto, O Nauroy, D Chouchan or C Milheres, P Bernat-Salles, L Mazas,
Referee: Chris White (England).