Vunipola, who was booed most times he touched the ball during his team's Champions Cup semi-final victory over Munster, again received jeers.
Just as it looked like the Irish side would be heading into the break with an advantage, the Sarries made a terrific comeback with a Sean Maitland try that had a conversion and a penalty from Owen Farrell on either side as the scores were levelled 10-10.
Prop Tadhg Furlong claimed a first-half touchdown for Leinster, while skipper Johnny Sexton added a conversion and penalty, but hopes of the Irishmen claiming a record fifth European title were dashed.
"We played some really good rugby in the second half, and I am just proud of the way the players have handled everything, really".
"You see the size of Billy Vunipola, Maro Itoje and Will Skelton and we don't have access to too many players of that stature and they certainly did wear us down". They were very clear on what we needed to do just a little bit better.
Celebrations started as soon as the final whistle came around - and especially so for Alex Goode.
Leo Cullen, the Leinster head coach, says the province will need to invest in their youth system if they are going to challenge in Europe again. There were so many different moments in the game. "You see the size of some of these Saracens players and they strangled us in the last 20-30 minutes - they are very comfortable in defence". "They're a big, big, physical team with lots of quality".
"When a team is trying to chase the game against them it becomes very hard because they are so aggressive in the middle of the field and are very comfortable defending and putting the squeeze on teams".
Sarries and England team-mate George said: "He is the best number eight in the world for me at the minute. They try and steamroller you".
"We probably didn't quite get it right today but it's tough out there". We've seen it a lot, where Saracens just get their noses in front, play pressure, pressure, pressure, pin us down, and they just squeeze the life out of teams.