Leinster saw their Heineken Cup crown slip through their fingers after being outfought at Le Stadium as Toulouse crept into the final with a 26-16 win.
The champions were defiant until the end but paid the price for leaking two tries to Yannick Jauzion and David Skrela in the space of four minutes heading into the final quarter.
Man of the match Skrela had the greatest impact on the scoreboard with a 16-point haul topped by his superb try, but Toulouse's scrum also did major damage.
Leinster suffered terribly at the set-piece and continued to struggle upon the arrival of South African CJ van der Linde after half an hour.
Van der Linde had replaced Cian Healy - the Ireland prop obviously culpable for the problems in the eyes of coach Michael Cheika - but Toulouse still dominated.
The tournament favourites and three-time winners had the perfect platform to attack while Leinster, whose line-out functioned well, often had to feed off scraps.
Jamie Heaslip's 65th-minute try gave the 4,000 travelling fans brief hope of a revival but that was soon extinguished when Skrela hit a fourth penalty to put Toulouse back in command.
Leinster travelled to France without their Ireland fly-half Jonathan Sexton but Shaun Berne proved a capable deputy, finishing with 11 points in a flawless display with the boot.