Ian Madigan starred as a second-half substitute in Leinster's bonus-point win over the Scarlets at the RDS.
Andrew Goodman scored a try and two penalties to give Leinster a 11-5 lead at half-time, with Andy Fenby going over for the Welsh visitors.
Madigan was involved in Leinster's most potent attacks as they scored 21 unanswered points after the break.
The fly-half converted tries from Aaron Dundon, Jordi Murphy and John Cooney in a comfortable Dublin victory.
The first quarter was pockmarked by penalties but both sides showed an eagerness to attack from deep and put the ball through hands.
Leinster edged ahead in the third minute with New Zealander Goodman, assuming the kicking duties for the night, planting a penalty through the posts.
The Scarlets' young half-backs Owen Williams and Aled Davies probed for openings off the fringes of rucks but Leinster were alive to the danger.
The visitors were reduced to 14 men after lock George Earle was carded for dangerous play at a lineout.
However, Goodman was unable to convert the resulting penalty and Williams also sent a penalty chance wide just past the midway point of the first half.
Simon Easterby's men boxed clever while Earle was off the pitch, keeping their defensive line intact apart from a Fionn Carr and Dominic Ryan-inspired surge.
Leinster began to build some momentum after a direct run from number eight Murphy.
A clever backhanded pass from Isaac Boss released David Kearney and their combined efforts led to Goodman's second three-pointer of the night.
The Kiwi then opened his try account for the province, swatting away Williams' attempted tackle to score in the right corner.
The pace and distribution skills of Carr, Kearney and Andrew Conway were to the fore in the build-up, with Goodman unable to convert from the touchline.
The Scarlets hit back straight from the restart, retrieving possession and hunting out to the left where Aaron Shingler and Aled Thomas combined to send Fenby streaking over in the corner.
Williams' conversion attempt went wide and Leinster also missed a couple of kicks closing in on half-time, Noel Reid hitting the left upright from closer range and Goodman pushing an effort wide.
Leinster used their lineout maul to good effect on the restart. A Shane Jennings drive to the line was ruled inconclusive, however hooker and man-of-the-match Dundon piled over from a similar attack soon after.
Madigan converted to put 11 points between the sides and just as the game seemed to be petering out, the out-half inspired Leinster's late bonus point push.
With 10 minutes left, Murphy took a great line onto a crisp pass from Cooney to score to the left of the posts with Madigan adding the extras.
Right at the death, Leinster turned defence into attack as Madigan and Fergus McFadden drove them on and replacement scrum-half Cooney sniped over from a close-range ruck to confirm the bonus point.
Leinster: D. Kearney, Conway, O'Malley, Goodman, Carr, Reid, Boss, J. McGrath, Dundon, Bent, Cullen, Marshall, Ryan, Jennings, Murphy.
Replacements: McFadden for Carr (48), Madigan for Reid (41), Cooney for Boss (64), O'Connell for J. McGrath (71), T. Sexton for Dundon (64), Hagan for Bent (64), Ruddock for Ryan (64).
Not Used: Flanagan.
Scarlets: A. Thomas, Reynolds, Maule, Warren, Fenby, O. Williams, A. Davies, John, E. Phillips, Adriaanse, Earle, Snyman, Shingler, Turnbull, McCusker.
Replacements: K. Phillips for A. Thomas (74), Ford for Reynolds (74), R. Jones for John (64), Rees for E. Phillips (46), Lee for Adriaanse (46), Timani for Earle (46), Ball for Shingler (64).
Not Used: G. Davies.
Referee: Marius Mitrea (Italy).
Assistant Referees: Michael Black, Jonathan Peak (both IRFU)
Citing Commissioner: Peter Ferguson (IRFU)
TMO: Dermot Moloney (IRFU)