Leinster dethroned defending Amlin Challenge Cup champions Biarritz to move within one win of their third European title in as many seasons.
Joe Schmidt's men ran out comfortable 44-16 winners at a sold-out RDS, where the province will host Stade Francais in the final on May 17.
Two tries from man-of-the-match Jamie Heaslip book-ended an evenly-balanced first half, with Leinster's precise passing and finishing being the difference at the break.
Dimitri Yachvili's third penalty in the 37th minute left Biarritz just 10-9 behind, only for Leinster to dazzle in the Dublin sunshine with two late tries.
Jonathan Sexton and Heaslip went over in a blockbusting three-minute burst, the former adding the conversions for a sudden 24-9 interval advantage.
The sin-binning of Takudzwa Ngwenya, early in the second period, was another blow for Biarritz, who will miss out on Heineken Cup rugby next year.
Isa Nacewa and Brian O'Driscoll added two more tries for the hosts, with Arnaud Heguy's consolation score reducing the margin to 28 points.