Leinster kept their hopes of Heineken Cup quarter-final qualification alive by scoring five tries in a bonus-point win over the Scarlets at the RDS.
Cian Healy, Shane Jennings and Luke Fitzgerald crossed the Scarlets' line in the first half and Rob Kearney and Ian Madigan scored further tries.
Jonathan Sexton added three conversions and Madigan one after his own try.
Liam Williams scored a try and kicked a drop-goal for the visitors, with Aled Thomas kicking two penalties.
Reigning Heineken Cup champions Leinster began the game in the knowledge that they must win both their remaining games with a bonus point to retain any realistic hopes of progressing to the last eight this time around, following two defeats by pool leaders Clermont Auvergne.
The Scarlets already knew that they would not make the last eight for the sixth successive season, having lost each of their first four group matches.
Thomas knocked over a third-minute penalty from in front of the posts but prop Healy barged over for the Irish province's first try five minutes later, Sexton adding the conversion.
Full-back Williams reduced the deficit with a sweetly struck drop goal and then flanker Jennings drove over after good work by the forwards following a lineout.
Leinster continued to pile on the pressure and their domination in the scrum set up the third try, Luke Fitzgerald diving over in the corner as the Scarlets defence succumbed again.
Sexton converted to increase the lead to 13 points, but the Scarlets ended the first half on a high after weathering the visitors' onslaught.
Thomas kicked across field, where Williams collected the ball and scored in the corner, to complete an outstanding team try.
Thomas was unable to add the additional two points on this occasion.
Kearney touched down for his side's crucial fourth try after just four minutes of the second period.
The Ireland international ran onto a fine switch pass from Jamie Heaslip and swivelled away from a couple of tackles before scoring the 16th try of his Heineken Cup career under the posts.
Sexton converted and then Thomas replied with his second penalty for the Scarlets.
A fit-again Brian O'Driscoll was introduced as a replacement for man-of-the-match Luke Fitzgerald in the 61st minute and caused some concern when he required treatment on his ankle late in the game.
Madigan raced through for a try in the final minute and quickly knocked over the conversion.
Leinster face a testing trip to Exeter Chiefs next Saturday, while the winless Scarlets host Clermont, who are already through to the quarter-finals as pool winners.
Leinster: Rob Kearney, Isa Nacewa, Fergus McFadden, Gordon D'Arcy, Luke Fitzgerald, Jonathan Sexton, Isaac Boss; Cian Healy, Sean Cronin, Mike Ross, Leo Cullen (capt), Devin Toner, Sean O'Brien, Shane Jennings, Jamie Heaslip.
Replacements: Aaron Dundon for Cronin (63), Heinke van der Merwe for Healy (41), Michael Bent for Ross (72), Tom Denton for Cullen (65), Rhys Ruddock for Jennings (58), Eoin Reddan for Boss (54), Ian Madigan for Sexton (72), Brian O'Driscoll for Fitzgerald (62).
Scarlets: Liam Williams, Andy Fenby, Gareth Maule, Scott Williams, Kristian Phillips, Aled Thomas, Tavis Knoyle; Phil John, Ken Owens, Jacobie Adriaanse, George Earle, Richard Kelly, Sione Timani, Josh Turnbull, Rob McCusker (capt).
Replacements: Matthew Rees for Owen (63), Rhodri Jones for John (63), Samson Lee for Adriaanse (49), Johan Synman, Tomas Vallejos for McCusker (59), Gareth Davies for Knoyle (49), Jonathan Davies for Maule (41), Adam Warren for L Williams (54).
Not used: Johan Synman
Referee: Jerome Garces (France)
Assistant Referees: Sébastien Cloute, Alexandre Ruiz (both France)
Fourth official: Barry O'Keefe (IRFU),
Fifth official: Brian Montayne (IRFU),
TMO: Jean Claude Levrier (FFR)