Leinster claimed the PRO14 title at Celtic Park in front of more than 47,000 fans.
Glasgow Warriors battled hard but couldn't come out on top against a Leinster side who were beaten in the Champions Cup Final earlier this season.
Stuart Hogg played his final game for Warriors but couldn't inspire them to victory as the Scotstoun side were narrowly beaten.
Just three points separated the sides at the final whistle after Grant Stewart's late try didn't finish with a conversion.
There was anger among the Glasgow support after Hogg was fouled by Rob Kearney in the air and the Warriors full back landed on his head.
A yellow was all that was shown when it could have easily been a red.
Warriors grabbed the opening score of the match when Matt Fagerson crashed over the line for the first try. Adam Hastings converted but Leinster hit back almost immediately although Jonny Sexton failed to put his conversion between the sticks.
Leinster led by five at half time after another try was converted by Sexton who then scored a penalty.
And when Kyle Steyn was sin-binned it looked to be a struggle and they fell further behind to another penalty from the Irish fly-half.
Kearney's yellow then sparked a mini-revival but Warriors could only get the score down to three and it's the second time they've been beaten in a final by Leinster.
