Bath's Heineken Cup adventure came to a soggy end as they were sunk by French champions Biarritz at a rain-swept Estadio Anoeta.

Biarritz made it third time lucky after two successive failed semi-final attempts, subduing a battling Bath outfit through five Dimitri Yachvili penalties and a Damien Traille drop-goal.

French international star Yachvili, scourge of England during the past three Six Nations campaigns, produced a faultless goal-kicking display in difficult conditions.

Although Bath, bidding to reach a first Heineken Cup final since they were crowned European champions in 1998, gave it everything, they lacked the guile and poise to break down a supremely-organised Biarritz defence.

Fly-half Chris Malone kicked three penalties for the English challengers, but they had England lock Danny Grewcock sin-binned late in the second half after a mass brawl which also saw Biarritz prop Petru Balan yellow-carded.

The northern Spanish coast had been drenched by rain ever since Bath arrived on Thursday and there was no respite during the game, with a slippery pitch making life difficult for both teams.

But Biarritz, despite never hitting top gear, always looked the more dangerous team and they will now meet Munster or Leinster in next month's Millennium Stadium final.

Bath's exit also means that England will have six places in next season's Heineken Cup, with France taking seven courtesy of Biarritz reaching the final.

Bath are now unlikely to qualify for top-flight European competition next term unless they win their remaining Guinness Premiership games against Sale Sharks and Worcester, while also hoping that other results work in their favour.

They created very few attacking opportunities, and it was not until the closing 15 minutes of a largely forgettable contest that they managed to make headway through the dangerous running of French wing David Bory and substitute Salesi Finau.

Bory though, was hauled down by a retreating Biarritz defence, and Salesi spilled possession with the line in sight.

The encounter was dominated by referee Alain Rolland, who gave both sides little leeway despite the often torrential rain, and was keen to punish every minor technical infringement.

Rival captains Borthwick and Benoit August were so perplexed by some of his interpretations that they held an impromptu discussion with the official on the touchline after their team-mates had left the field for half-time.

With the playing surface making adventurous rugby virtually impossible, Rolland needed to show more empathy, but the Irish official did not relent and there was precious little for a crowd of just under 30,000 to enthuse about.

Yachvili opened Biarritz's account with a fifth-minute penalty, a lead that he doubled 11 minutes later after Bath prop Duncan Bell required prolonged treatment for an injury.

Malone and Yachvili then exchanged penalties during a four-minute spell, before Malone's second successful strike meant Bath ended the opening half just three points adrift and with hopes high of causing an upset.

But, as with all quality sides, Biarritz took charge, raising their game when they needed to as Yachvili slotted a fourth penalty and Traille dropped his goal within eight minutes of the second period getting underway.

Bath, without doing little wrong, were suddenly 15-6 adrift and facing an uphill struggle.

They produced their best rugby during the closing 15 minutes, but Malone's third penalty was the only reward for their efforts after coach Brian Ashton tried to shake things up by moving centre Olly Barkley to full-back and sending on Samoan centre Eliota Fuimaono.

Bory and Finau both had chances to cause a major upset, but Biarritz kept their composure when it really mattered and the unflappable Yachvili had the final say through his deadly left boot, leaving Bath to reflect on a failure at the penultimate hurdle.

Biarritz now go on to the final on May 20, but Leinster or Munster, who meet in Dublin on Sunday, have little to fear on the strength of this evidence.