A desperately poor first quarter performance from Leinster gave them little chance of beating Llanelli on Saturday but coach Michael Cheika watched his side almost come from behind.
Leinster's day began and finished with heart rates fluttering as traffic delayed the squad on their way to Stradey Park and their all-action final quarter saw them pressing for a bonus point-clinching fourth try.
Having conceded tries to Dafydd James (2), Inoke Afeaki and Regan King within the first 24 minutes - the Scarlets led 27-0 for a time - Leinster, despite a truly awful day at the office with the lineout in abysmal shape, the forwards looking disjointed and the backs faring little better, drew on all their reserves to produce a credible fight back.
They were helped on their way when Dwayne Peel's loose pass was gleefully snapped up by Denis Hickie in midfield and the Ireland winger raced 60 metres to the try line.
Leinster's 27-7 interval deficit was cut back to 27-14 and then 30-21 as tries from Hickie and lock Trevor Hogan sandwiched a lone penalty strike from Stephen Jones. There was no further joy for Leinster - their revival was stalled as Jones' third penalty of the evening pushed the Scarlets to safety.
Cheika said afterwards: "We got into a position where we could have won the game, when a lot of teams might have let their heads drop.
"We were physical but we've got to cut down on our errors. We lost Rob Kearney with a hamstring when it looked like we were going to score so it was one of those nights. With 17 minutes to go I thought we were going to win, but I am disappointed to have come away with nothing."