Leinster will face Toulouse in the final of the Investec Champions Cup.
The French side survived a topsy turvy second half to beat Harlequins by 38 points to 26.
They will meet the Blues in the decider at the Tottenham Hotspur Stadium in three weeks time.
Advertisement
Elsewhere, Leinster have signed Jack Boyle to his first senior contract.
The prop makes the step up from the Academy after 9 appearances for the Blues.
