Fly-half Jonny Bentley ended the game with an 18-point haul
Cornish Pirates inflicted a first British and Irish Cup defeat of the season on Leinster with a 43-12 win.
The hosts started strongly when flanker Tyrone Holmes's try was followed by one by Jonny Bentley - who converted both.
Noel Reid replied for Leinster but the Pirates raced to a commanding 36-5 half-time lead with scores from Wes Davies, Rhodri McAtee and Tom Luke.
Pirates won a penalty try after the break before Leinster were rewarded by Michael Keating's late touch down.
The win leaves the Cornish side top of Pool A, with maximum points. Leinster are in second place, with nine points.