Leinster secured a fourth Champions Cup crown thanks to a 78th-minute penalty from departing wing Isa Nacewa, his strike sealing a 15-12 win over Racing 92 who were missing Dan Carter.
Carter was ruled out of this morning's (NZT) final due to a hamstring injury.
Carter will leave the French club at the end of the season after signing a two-year deal with Japanese side Kobe Steelers.
The 36 year-old former All Black outhalf was hoping to end his top-class rugby career with one of the few medals that has so far eluded him.
He has won 112 caps, nine Rugby Championships and two World Cups with New Zealand; three World Player of the Year awards - evenly spread from 2005, 2012 and 2015 - four Super Rugby titles with the Crusaders and two Top14 wins with Perpignan and Racing.
The French side took the lead four times throughout the contest at the San Mames Stadium in Bilbao, thanks to their impressive scrum-half Teddy Iribaren.
Leinster, not at their best thanks to Racing's defensive pressure, stayed in the game thanks to three penalties from Johnny Sexton.
But it was Nacewa who clinched the win, knocking over his second three-pointer two minutes from time. Remi Tales, a late call-up for Racing, had the chance to take the game to extra-time but pushed his drop goal wide.
-More to come