Leinster completed a comfortable double at Cardiff Arms Park to see off Cardiff Blues 26-11 and consolidate their position in the RaboDirect Pro12 play-off places.
The Blues had been enjoying something of a revival at home, with three successive wins in three different competitions, but were outmuscled up front and out-thought at the back in a disastrous first half, meaning even a gallant fightback after the break was never going to be enough.
Both sides showed plenty of enthusiasm in a lively opening before Leinster took the lead with the first of four Ian Madigan penalties. Isaac Boss and Jordi Murphy crossed over for the away side as Madigan added the extras to take his points tally to 16. Jason Tovey scored a second-half try for the Blues and Rhys Patchell kicked over two penalties.
Meanhwile, fly-half Owen Williams kicked 20 points as the Scarlets sealed a 25-15 victory over Connacht at Parc y Scarlets.
Lock Joe Snyman scored the Scarlets only try - his first try for the region.
But the Welsh side found themselves out-scored two tries to one by Connacht who were indebted to scores from wing Daniel Poolman and lock Mike Swift at either end of the contest.