Biarritz - 32 Leinster - 21 In its way, this quiet, slow retreat from the south west of France was just as painful and even more poignant than Leinster's semi-final defeat at home to Perpignan last season. That will always be rightly regarded as their best chance of Euro glory, but Saturday's defeat may effectively mark their last chance.

The end of an era? If felt like it. It's not just the doubts about the continuing longevity of the older guard up front, but the potential exodus of their talented backs as well. Word filtered through the Leinster camp that Brian O'Driscoll had reiterated the distinct possibility of moving to France at the end of the season on the Late Late Show on Friday night if he felt that might bring about a better chance of winning trophies.

Sadly, this result might lead him to just such a conclusion, and the further ripple effect could see the likes of Denis Hickie, Shane Horgan and Gordon D'Arcy go, perhaps even Malcolm O'Kelly as well, all of whom are being coveted by the leading French clubs.

And in the heel of the hunt, they weren't even good enough to get out of this pool - by no means the strongest of the six. There have been a host of mitigating factors, not least the injuries to O'Driscoll and Hickie, and of course, the Felipe Contepomi registration gaffe, and the Irish get-togethers before the home defeat to Sale can't have helped.

Furthermore, it was perhaps inevitable the loss of first Alan Gaffney and then Matt Williams has contributed to a marked decline as well, and the jury is at best still out on whether Gary Ella was the best choice to succeed them. He was dealt a tough hand, and looking at them misfire for much of the first hour in this crunch tie the inescapable conclusion was that not enough players were up to this level.

Virtually all the pre-match concerns about this Leinster team were borne out, and one or two more. Given the magnitude of the outcome and the high stakes, it seemed inconceivable Leinster could play so badly until the introduction of Brian O'Riordan especially, Shane Jennings and Gavin Hickie sparked a higher tempo, two tries and five minutes of injury time in which to obtain the try which would, amazingly, have put them through to the quarter-finals.

It would have been quite a steal. Biarritz had dominated up until then, Serge Betsen and Ovidiu Tonita leading a much more aggressive defensive line, their lineout maul causing Leinster untold problems, and Nicolas Brusque oozing class.

They scored five tries, might have scored a few more, and saw Dimitri Yachvili miss four kicks out of four in the first half at the end of which, perversely, Leinster could have been leading had John McWeeney been more alert before having the ball knocked from his grasp well over the line by Brusque when attempting a one-handed touch down.

Leinster's lineout was good, stealing three throws to one, and their scrum survived okay, but because of their declining back play and defence, nowadays their pack needs to do more than that.

Well though Biarritz played in patches, they were given every invitation to do so by their visitors, be it through handling errors, needless turnovers, wrong options, or silly penalties.

If one incident underlined that Leinster just didn't have the collective intensity for the occasion it came within two minutes of the resumption. Girvan Dempsey took the ball back into contact on half way, but only Aidan McCullen hit the ruck as his team-mates either stood off or were too slow to regroup. Four Biarritz forwards drove over the ball, and they duly went downfield for Thomas Lievrement and Betsen to put Jimmy Marlu over on the blind side of a lineout maul.

Frankly, Leinster's defence has gone backwards, in every sense, this season, and they hardly made an aggressive hit all day. The ability to absorb pressure, as in making 125 tackles when keeping Montferrand scoreless last season, has evaporated. Injuries have seriously disrupted their defensive training this season, but they haven't spent as much time on it either, and it shows.

For the first try, Biarritz went up the middle off a short lineout, recycled it twice and went blind again. Leinster had the numbers but Brusque was able to take the tackles of Brian O'Meara and McWeeney to score. In such a huge game, it's hard to believe they would have conceded that try a year ago.

With the ball, their continuity isn't bad, but they have become predictable, and are reliant on individualism, mostly from D'Arcy, who manfully wriggled yards out of nothing and made a couple of incisions in another tour de force. Horgan, who started the campaign so well with his two-try performance against the same opponents, is being made to look a one-dimensional crash-ball merchant.

The lack of spark from the halves, where Christian Warner looked short of match time and practice time, was underlined by O'Riordan's impact at scrumhalf. Suddenly they came alive, none more so than Dempsey, who ran in D'Arcy's break and offload.

It said everything about the lack of variation heretofore that O'Kelly's chip in the build-up to Keith Gleeson's try off Warner's skip pass was the first use of the tactic by a Leinster player all day.

Dempsey's second touchline conversion raised the possibility of an unlikely escape route, for a fourth try would have taken them to within seven points of Biarritz and earned them two bonus points, putting them through.

However, unforgivably, not everyone knew this, including some of those on the pitch and the touchline. Brendan Burke's kick downfield from the restart rather than keep the ball in hand was proof of that.

Once again, Leinster were on the threshold of building some serious momentum, as they were again loudly and superbly supported by about 500 supporters. Although played on a watered pudding of a pitch, conditions were pleasant and the atmosphere was far from intimidating.

The immense repercussions of this setback go beyond even the possible break-up of this team. The loss of revenue from not reaching the knock-out stages can be put at anything between €250,000 and €300,000, not to mention the marketing of the Leinster Lions' brand name. And most of all perhaps, the incalculable hangover of having only the Celtic League to play for.

The younger guard will now attempt to revive Leinster's season. The baton, you sense, is being passed on, which is what made this a particularly sad day.

SCORING SEQUENCE: 11 mins: Brusque try 5-0; 30 mins: Brusque try 10-0; 34 mins: penalty try 10-7; (half-time 10-7); 42 mins: Marlu try, Yachvili con 17-7; 58 mins: Yachvili try and con 24-7; 60 mins: Betsen try 29-7; 68 mins: Yachvili pen 32-7; 71 mins: Dempsey try and con 32-14; 81 mins: Gleeson try, Dempsey con 32-21.

BIARRITZ OLYMPIQUE: N Brusque; P Bidabe, M Stcherbina, J Isaac, J Marlu; J Peyrelongue, D Yachvili; P Balan, J Gonzalez, D Avril, H Manent, D Couzinet, S Betsen, T Lievremont (capt), O Tonita. Replacements: D Chouchan for Tonita (13-17 mins); P Bernat-Salles for Marlu (50 mins); D Minassian for Balan (65 mins); S Puleoto for Couzinet (79 mins); M Fitzgerald for Avril, L Mazas for Bidabe (both 82 mins).

LEINSTER: G Dempsey; J McWeeney, G D'Arcy, S Horgan, B Burke; C Warner, B O'Meara; R Corrigan (capt), S Byrne, P Coyle, M O'Kelly, B Gissing, A McCullen, V Costello, K Gleeson. Replacements: S Jennings for McCullen (62 mins); B O'Riordan for O'Meara (65 mins); G Hickie for Byrne (69 mins).

Referee: Nigel Williams (Wales).