Toulon's bid to make history faces another examination in sunny Marseille on Sunday when they take on Leinster.
These two teams have dominated European rugby in recent times, winning five of the last six titles between them and the last four in a row.
No side has ever won three straight European titles, with Leicester and Leinster the only two teams to be in this position before.
Leicester's charge in 2003 ended when Munster stormed Welford Road in the quarter-finals, while Leinster couldn't get out of their pool two seasons ago as they twice fell to Clermont Auvergne.
Toulon's road to being two games away from a hat-trick hasn't been as rocky. Bernard Laporte's all-star squad were defeated on their visit to Leicester but by winning their five remaining matches qualified as second seeds.
Wasps certainly had their moments in the quarter-final, initiating a second-half fightback that kept the Toulon newspapers for the time being in the hands of their supporters. Only when Ali Williams scored were they finally released into the air, a sight that we've become accustomed to as Toulon have backed up their investment with incredible success.
Collecting trophies doesn't come down to luck though. Toulon's work-rate is outstanding and their tactics for winning matches aren't exactly rocket science.
A strong set-piece, an array of experts at the breakdown along with their clinical attack and impressive ability to retain possession through multiple phases all make Toulon into a rigorous test of the opposition's mental and physical strength. Take down Steffon Armitage and Chris Masoe, next you have Mathieu Bastareaud. It's neverending.
Leinster at least know what to expect, having taken on Toulon last year in the quarter-final at Stade Felix Mayol.
The Irish province were always well in that contest until around the 60-minute mark and the lessons taken from that defeat will have been invaluable ahead of Sunday.
Matt O'Connor's team just know that first-up tackles have to be made and that they cannot miss any chances that fall their way. Knowing that however is the easy part.
After some indifferent form in the PRO12, pulling off an upset in Marseille would be a remarkable achievement and perhaps even ease the pressure on O'Connor from certain groups of Leinster supporters who have never warmed to him since his arrival from Leicester, despite last season's league title.
It's a hell of an ask, even with Leinster's pedigree of having won three of their last four European semi-finals – the last one of course being that memorable triumph at the fortress Stade Marcel Michelin over Clermont. That is the standard they have to match.
Leigh Halfpenny is crucially fit for Toulon to start at full-back, where he will be their primary goalkicker, while Delon Armitage and Bryan Habana start on the wings in two changes from the quarter-final. Matt Giteau returns at inside centre with Juan Smith being the other tweak at blindside flanker in place of Mamuka Gorgodze.
Leinster meanwhile have gone with the same starting XV which triumphed over Bath two weeks ago in Dublin, with the only change to the 23 being Ben Marshall's selection on the bench. Ian Madigan partners Ben Te'o in midfield.
Players to watch:
For Toulon: The absence of Steffon Armitage puts the onus on Chris Masoe at the breakdown, as the former All Black packs down at number eight. It says plenty about Masoe's quality that Racing Métro are eager to sign him up for next season when his contract expires at the age of 35. Prominent in Toulon's carrying game too.
For Leinster: Points will be precious on Sunday and that puts the spotlight on Ian Madigan to be as perfect as possible off the kicking tee. The top scorer in this year's pool stages with 80 points, eight more than Leigh Halfpenny, the Ireland international has also been a key carrier for Leinster, beating 14 defenders to date. His defensive work will be scrutinised as well by Toulon's runners after he missed five tackles in the quarter-final win over Bath.
Head-to-head: Leinster need a strong set-piece and Devin Toner is crucial in that regard, as he goes up against the experienced Springbok in Bakkies Botha.
Toner has established himself as a key cog for Ireland and is the main man in Leinster's lineout, with 25 takes so far. Leinster will also hope that Cian Healy can get on top of Carl Hayman in the scrum, making Toner's effort in the second-row all the more important. As for Botha, the old enforcer is showing no signs of slowing down and will make his presence felt. The big games seem to bring the best out of him.
Prediction: Leinster possess a number of internationals and are a match for any side on their day, but Toulon look irresistible as they look to power their way through to a third straight European final. Toulon by 8!
Toulon: 15 Leigh Halfpenny, 14 Delon Armitage, 13 Mathieu Bastareaud, 12 Matt Giteau, 11 Bryan Habana, 10 Frederic Michalak, 9 Sebastien Tillous-Borde, 8 Chris Masoe, 7 Juan Fernandez Lobbe, 6 Juan Smith, 5 Ali Williams, 4 Bakkies Botha, 3 Carl Hayman (c), 2 Guilhem Guirado, 1 Xavier Chiocci.
Replacements: 16 Jean-Charles Orioli, 17 Alexandre Menini, 18 Levan Chilachava, 19 Steffon Armitage, 20 Drew Mitchell, 21 Rudi Wulf, 22 Michael Claassens, 23 Jocelino Suta.
Leinster: 15 Rob Kearney, 14 Fergus McFadden, 13 Ben Te'o, 12 Ian Madigan, 11 Luke Fitzgerald, 10 Jimmy Gopperth, 9 Isaac Boss, 8 Jamie Heaslip (c), 7 Sean O'Brien, 6 Jordi Murphy, 5 Mike McCarthy, 4 Devin Toner, 3 Mike Ross, 2 Sean Cronin, 1 Cian Healy.
Replacements: 16 Richardt Strauss, 17 Jack McGrath, 18 Martin Moore, 19 Ben Marshall, 20 Dominic Ryan, 21 Eoin Reddan, 22 Gordon D'Arcy, 23 Zane Kirchner.
Date: Sunday, April 17
Venue: Stade Velodrome, Marseille
Kick-off: 16:15 local (14:15 GMT)
Referee: Wayne Barnes (Eng)
Assistant Referees: Nigel Owens (Wal), Greg Garner (Eng)
TMO: Graham Hughes (Eng)