© Getty Images
Toulon thought they had opening the scoring with a try when Chris Masoe touched down past the line, but the referee blew his whistle for offside. However, the French side did earn a penalty and Leigh Halfpenny fired them ahead with his kick through the posts.
Leinster responded with a good spell of pressure which earned them a penalty and they opted to attempt to tie the scores with a kick from close range. Ian Madigan made no mistake as he levelled things up with an accurate kick.
The Irish's side pack was forcing errors from Toulon, which paved the way for them to take the lead as they earned another penalty which was dispatched by the boot of Madigan. Minutes later, the 26-year-old increased his side's advantage to six points with another effort between the posts.
In the second half, Halfpenny was presented with the opportunity to bring his side level, but he put his kick from the sideline wide of the uprights.
However, the Welshman found his range minutes later to tie the scores, while Jordi Murphy was then penalised for not rolling away, giving Halfpenny a kick right in front of the posts to fire his side in front with 10 minutes to play.
Leinster responded through the boot of Madigan as he held his nerve to kick from 40m and level the scores once more.
Jimmy Gopperth narrowly missed a drop goal to put the Irish side into the lead in the dying minutes and his wayward effort nearly cost his team as Toulon raided back upfield and were awarded a penalty. However, the kick from 55m was missed by Delon Armitage to send the match into extra time.
At the start of extra time Halfpenny and Madigan exchanged kicks to leave the scores tied at 18-18. However, Madigan was to make a crucial error as his pass was intercepted by Bryan Habana, and the winger ran it all the way back to notch the first try of the game.
Leinster battled back with a try of their own as Sean O'Brien found a gap in the Toulon line to power over for the score, but the conversion from Gopperth came back off the post to leave the scores at 25-20 with time running out.
The Irish side were unable to score again which sent Toulon through to the final of the competition where they will face Clermont.