The Scarlets found the temperature at Lansdowne Road considerably higher than whatever figure this April heatwave is pushing the mercury too. They were utterly smithereened by an astonishing Leinster performance which had as its kernel a pace and intensity that didn't allow Scarlets time to breathe. The final score read 38-16, with Tadhg Beirne touching down late on for a late consolation try, but it was a scoreline that flattered the Welsh side.
Leinster led 24-9 at half-time through tries from James Ryan, Cian Healy and Fergus McFadden and made it considerably more comfortable with a brace of tries from Scott Fardy and Johnny Sexton.
Utterly dominant: Leinster march on to the final in Bilbao. Here are the Leinster player ratings.
Rob Kearney - 7
Relatively quiet afternoon's work for Kearney in which he was untested defensively. Some of his kick chases were impressive, and he also tried another wildly ambitious drop goal early in the second half which, to be honest, we're all for.
Fergus McFadden - 8
Ultimately injured while touching down for Leinster's third try on the stroke of half-time, which brought a premature end to a fine performance. McFadden's workrate was ferocious, and it was the alacrity of his kick-chase which laid the platform for the move that ended with his try. McFadden is mining a rich lode of form at the moment.
Garry Ringrose - 8
Oozed class throughout, and created two of the first half tries: a canny decoy run bewitched a couple of Scarlets defenders for James Ryan's try, while his pass wide to McFadden before half-time was perfect.
Robbie Henshaw - 8.5
We're not quite sure where Henshaw found that performance. Returning from a ten-week layoff, Henshaw arrived ravenous to gobble up every blade of Lansdowne's grass. He flung himself at the Scarlets defensive line with an enthusiasm that didn't diminish, making an average of three metres with each of his eight carries.
Isa Nacewa - 6
Nacewa struggled with illness in the build-up to the game, and was largely uninvolved here.
Johnny Sexton - 8
Standard fare from Johnny: flawless off the tee, superb with ball in hand, tough in the tackle, and he crowned it all with a try which triggered effusive celebrations and the end of his afternoon.
Jamison Gibson-Park - 8.5
A fine performance. He enjoyed playing behind a pack that smithereened the Scarlets pack, but did a good job of maintaining Leinster's ferocious flow. His kicking was good, too: a great box-kick from his own five-metre line ultimately ended in McFadden's try.
Cian Healy - 8
This was a semi-final performance to rival the famous win away to Clermont in 2012, and once again, it featured a Cian Healy try. The prop's renaissance reason is proving to be a sensational one, and this was its latest installment. His first-half try owed much to his dynamism on the ground to snaffle the ball just before John Barclay could pounce, and bar one dodgy scrum in which he lost his bind on Samson Lee, this was an outstanding performance.
Sean Cronin - 7.5
With Leinster having so much joy with ball in hand, they weren't forced to involve the lineout as a necessary instrument for victory. It still functioned well when they needed it, on a fine afternoon's work for Cronin.
Tadhg Furlong - 7.5
Struggled occasionally in the scrum, with Scarlets winning two penalties at the set piece in the first-half. No matter: Furlong still performed well, making six tackles.
Devin Toner - 7.5
Tadhg Beirne is going to put Toner under pressure for his World Cup place next season, but here Toner performed well, ruling the skies at lineout time.
James Ryan - 8.5
Ryan's performances are routinely astonishing, and this was no different. He showed remarkable power to spring to his feet and shake off Ken Owens for the opening try, and from there blew the Scarlets forwards off the field, and left the field after 70 minutes as Leinster's top tackler with 12. Remarkable.
Scott Fardy - 8.5
His contribution to Leinster's season could yet eclipse Rocky Elsom's to the European Cup-winning season of 08/09. Played a rarely-seen one-two with James Ryan before driving over to seal the game early in the second half.
Dan Leavy - 8
Yet another ferocious afternoon's work for Leavy, with only James Ryan making more tackle for Leinster. The quality of his ball handling in contact was evident this afternoon, and one of the many, many reasons Scarlets were completely overwhelmed.
Jordi Murphy - 7
Murphy was the least conspicuous of Leinster's forwards, outshone by Fardy and Ryan in particular. Nonetheless, he still made nine tackles and will fancy his chances of keeping hold of his starting jersey in Bilbao, which might become a sweet farewell ahead of his move to Ulster next season.