A stoppage-time try and conversion off the inside of the post denied Scarlets a famous win over three-time European champions Toulon at their Stade Mayol fortress.
The Welsh side, who played the second half with 14 men following the sending off of lock Tevita Ratuva, led 16-10 with an incredible 90 minutes played of an ultra-tense European Challenge Cup tie, but ultimately were unable to hold on in the dying seconds.
It was an outstanding display of character and tenacity from the Scarlets, but a display that deserved more ended in heartbreak when Liam Messam was driven over from a close-range line-out and Anthony Belleau sneaked over the conversion.
Heavy rain had fallen most of the day in Toulon, but it had thankfully relented by the time the players took the field at the Mayol.
The Scarlets started well with returning Wales internationals Ryan Elias and man of the match Aaron Shingler prominent, but it was the home side who struck first after nine minutes with wing Gervais Cordin latching onto a clever cross-field kick from fly-half Louis Carbonel. French international Belleau converted.
However, the Scarlets hit back quickly and it was new Wales squad member Johnny McNicholl who provided the inspiration when he intercepted Belleau’s ambitious pass from 40 metres out and raced to the line unopposed.
Ryan Lamb added the extras and the scores were level after 15 minutes.
Josh Macleod produced a couple of superb turnovers to keep Toulon at bay as the home side pressed in the second quarter.
Belleau moved the score to 10-7 after Juandre Kruger - playing against his former side - was penalised for a high challenge, then Belleau missed a kick which would have extended the advantage.
The determined defence looked to have got the Scarlets to the interval unscathed, but in the final minute of the half, Ratuva was dismissed for a dangerous challenge at a ruck with referee Tom Foley showing the Fijian red following consultation with the television match official.
The Scarlets, though, refused to bow to their hosts and took the game to Toulon after the break.
It remained 10-10 until the 67th minute when replacement Dan Jones slotted over a penalty from 43 metres in front.
Moments later, the vocal Scarlets faithful were celebrating another three-pointer from the boot of Jones, courtesy of a superbly-taken drop goal.
Then came the late drama.
A couple of penalties saw the Scarlets camped inside their own 22, leading to a series of attacking scrums for the home side.
The Scarlets, with Steff Hughes packing down at No. 8, managed to hold out, but when Toulon opted for an attacking line-out drive in the 90th minute, they had enough power to drive Messam over.
It was left to Belleau to hold his nerve with the conversion in what was a cruel finale for the Scarlets and their outstanding supporters.
Toulon - tries: G. Cordin, L. Messam. Cons: A. Belleau. Pen: Belleau
Scarlets - try: J. McNicholl. Con: R. Lamb. Pens: Lamb, D. Jones. D-g: Jones.
Referee: Tom Foley (England)