Scarlets secured a place in the knockout stages of the European Challenge Cup thanks to a bonus-point 33-14 victory over London Irish on a night to remember at the Madejski Stadium.
Pau’s failure to claim a five-point haul in their game against Leicester Tigers had left the door open for the Scarlets to make the quarter-finals and the team went charging through, inspired by an incredible away support.
More than 500 fans sung their way from start to finish as the Scarlets claimed the four tries they needed to progress.
Corey Baldwin, Dan Jones, man-of-the-match Kieran Hardy and wing Steff Evans crossed; a dominant pack earned a penalty try, while outstanding full-back Leigh Halfpenny kicked three conversions.
A clash with Toulon in the south of France in the first week of April now awaits Brad Mooar and his men.
The Scarlets recovered from an early setback which had seen Irish strike first through powerful Fijian No. 8 Albert Tuisue, who burst through a couple of tackles to cross at the posts - a try converted by fly-half Stephen Myler.
But the Scarlets response was swift.
The pack set up a good attacking position and a clever move found Halfpenny, who twisted out of the tackle before feeding Corey Baldwin.
The right wing still had a bit to do, but showed great pace to outstrip the cover from 25 metres out and dive over.
Halfpenny levelled matters with the conversion and it wasn’t long before the vocal travelling support were celebrating a second try.
Tevita Ratuva carried to within inches of the line and when the ball came back, fly-half Jones did well to get on the outside of the defender and then twist over.
The television match official had a good look first, but agreed with the visiting support and the score was given.
Halfpenny’s conversion made it 14-7 as the Scarlets started to take a grip on proceedings.
With the pack enjoying an edge at the scrum, the visitors were able to set up a strong territorial position.
Irish halted a driving maul illegally, but the Scarlets were not to be denied as scrum-half Kieran Hardy took a quick tap penalty and dived over.
Halfpenny’s third successful conversion took the score to 21-7 and a healthy half-time advantage for the Welsh side.
Needing another try for the bonus point, Scarlets fans didn’t have to wait long.
Irish had hooker Saia Fainga’a sin-binned for illegally pulling down a maul and from the scrum that followed, the Scarlets pack shunted the home eight across the line to earn a penalty try.
Steff Evans narrowly failed to hold onto a kick through, but then made no mistake from a clever dink from Dan Jones to claim try number five on 56 minutes.
With the fans in party mood, the game was now in the bag as the Scarlets emptied the bench.
Irish claimed a second through that man Tuisue, but it didn’t dampen the spirits as the players and fans celebrated a memorable night at the final whistle.
London Irish - tries: A. Tuisue (2). S. Myer (2)
Scarlets - tries: C. Baldwin, D. Jones, K. Hardy, pen try, S. Evans. Cons: L. Halfpenny (3).