But, with pool leaders Clermont having secured a quarter-final place with their win over Exeter Chiefs in France, Leinster - who have won three out of the last four Heineken Cup finals - still face the prospect of being knocked out at the pool stages of the tournament for the first time since 2008.

The triple champions still have to come away with all the points on offer when they travel to face Exeter in their last Pool 5 game next weekend to give themselves a chance of a best runners-up place.

The Scarlets, who had nothing to play for but pride, have still to win in this season's Heineken cup and slumped to their seventh defeat in eight games in all competitions at the RDS.

Fly-half Aled Thomas slotted an early penalty for the Scarlets to give them a three-point lead before Leinster's Irish international prop Healy burrowed over from short-range to secure a lead his side would never surrender.

Sexton added the conversion before the Scarlets full-back Liam Williams landed a speculative drop goal from long range to make it 7-6 to the home side midway through the first half.

But it wasn't long before Leinster crossed for their second try when openside Jennings barged his way over from the back of a driving maul after a well-worked lineout on the Scarlets line to make it 12-6.

Fitzgerald claimed Leinster's third try before Scarlets centre Scott Williams' cross-kick found his full-back and namesake, Liam, for a try that made it 19-11 at half-time.

Kearney's try just after half-time secured the vital bonus point before replacement fly-half Ian Madigan crossed for Leinster's fifth try to put a gloss on the win late on.