Llanelli's Heineken Cup dream was destroyed at an emotion-charged Stradey Park tonight as French challengers Perpignan produced a stunning quarter-final upset.
And just to make Llanelli's misery complete, they had their Welsh international flanker Dafydd Jones sent off for stamping after just 10 minutes.
Australian fly-half Manny Edmonds was the Perpignan hero, kicking 16 points from two drop-goals, two penalties and conversions of an early penalty try and number eight Phil Murphy's 37th-minute touchdown.
Llanelli threw everything at their visitors during the closing moments as they tried desperately to erase a seven-point deficit, but it was not to be.
A Scarlets victory would have secured a third Heineken Cup semi-final appearance in four seasons, yet 25-1 outsiders Perpignan now march on towards a last four appointment with either Leinster or Biarritz later this month.
Llanelli saw Jones dismissed by English referee Tony Spreadbury.
It was Jones' second red card in the Heineken Cup this term. On the previous occasion - at Sale last October - his sending off was deemed sufficient punishment, but tournament disciplinary chiefs were unlikely to be so lenient this time around.
Jones' use of the boot - on Perpignan scrum-half Ludovic Loustau's head - gave his team-mates a mountain to climb.
Although Llanelli responded magnificently at times, Perpignan had enough in the tank - backed up by a colossal defence - to become the first French side in 18 attempts to win a European tie on Scarlets' soil.
Fly-half Stephen Jones threatened a Llanelli victory, kicking four penalties and a conversion of prop Martyn Madden's 25th-minute try, which Jones set up through a slashing midfield break.
Perpignan were ferociously tough opponents though, giving Llanelli a severe examination in all departments.
Perpignan went ahead inside two minutes when Spreadbury awarded them a penalty try following deliberations with video official Ed Morrison.
Spreadbury ruled that Scarlets flanker Simon Easterby had tackled Perpignan full-back Jean-Marc Souverbie without the ball on Llanelli's line.
Edmonds converted, and also improved Canadian number eight Phil Murphy's try for a 14-13 interval advantage, before two further penalties kept Llanelli on the back foot.
Perpignan lock Jerome Thion was sin-binned during the frantic closing stages, yet there was nothing Llanelli could do to smash down an imposing defensive wall.
Not since Llanelli beat Leicester in a Heineken Cup group game last season had the Scarlets' historic rugby citadel witnessed such a pre-match atmosphere.
The sold-out signs went up weeks ago, and a capacity 10,800 crowd packed into Stradey Park as a Llanelli side containing 14 internationals took on Perpignan, pool stage conquerors of both Gloucester and Munster this term.
If Llanelli began the game as firm favourites, then Perpignan's wake-up call took just 61 seconds to ring out loud and clear.
From their first attack, the French side weaved through Llanelli's defence, and Souverbie sprinted away in pursuit of his own kick.
It all ended with the penalty try award, and Llanelli were stung into action, with Jones slotting a seventh-minute penalty following relentless forward pressure.
But Llanelli's night suddenly turned sour, when Jones' moment of madness saw his side reduced to 14 men with 70 minutes still remaining.
Spreadbury had no hesitation brandishing the red card, leaving Jones to reflect on his reckless act as he trotted off the pitch, and leaving Perpignan holding a significant advantage.
Another Jones penalty cut the deficit to 7-6, then Llanelli unlocked Perpignan's defence as a supporting Madden crashed over in support of his fly-half's decisive act.
The Scarlets could not build or consolidate a lead though, and Murphy's score, followed by 12 further Edmonds points secured an outstanding French success.
While the Perpignan players celebrated, Llanelli could only contemplate on where and why it went so badly wrong.
The massed Stradey Park chorus left for home in stunned silence.