Should Leinster beat Toulon, they will face another French side in the Champions Cup final
Clermont Auvergne 13 Saracens 9
Saracens bowed out of the European Champions Cup after a brave and battling display at Stade Geoffroy-Guichard as English representation in this season's competition came to an agonising end.
France star Wesley Fofana scored the game's solitary try just after half-time as French heavyweights Clermont prevailed 13-9 to reach their second European final in three seasons.
Defending champions Toulon or Irish challengers Leinster await them at Twickenham next month - they clash in Marseille on Sunday - but Saracens were left to reflect on what might have been following a performance packed with courage and intent.
Charlie Hodgson and Owen Farrell each kicked penalties, while Hodgson also dropped a goal, but Clermont triumphed through Fofana's sweet finish, plus a Brock James conversion and two penalties.
Clermont did not remotely have things their own way, though, having arrived in the semi-finals following a 37-5 rout of reigning Aviva Premiership champions Northampton a fortnight ago.
Saracens pushed them every inch of the way, giving as good as they got in all areas of a fiercely-contested encounter, but arguably Clermont's greater big-match European experience told as they avenged last season's 46-6 semi-final Twickenham humiliation.
It was not pretty, and there was little gilt-edged attacking rugby on show from either team, yet it proved to be absorbing, attritional battle that ultimately went Clermont's way.
Saracens are now left to focus on domestic matters, and their current form is such that it would be no surprise if they ended the season as Premiership title winners.
England centre Brad Barritt captained Saracens in the absence of an injured Alistair Hargreaves, while flanker Jacques Burger returned from suspension to pack down alongside back-row colleagues Maro Itoje and Billy Vunipola, and Farrell featured on the bench after three months' sidelined because of a knee problem.
Clermont showed one change from the side that thumped quarter-final opponents Saints a fortnight ago as Julien Bardy replaced an injured Fritz Lee in the back-row and skipper Damien Chouly moved to number eight.
Clermont probably had 90 per cent of support inside the stadium, and the 2013 European runners-up began strongly, looking to unleash full-back Nick Abendanon in open play as they strived for an early opening.
Saracens, though, defended well, even if they needed a stroke of luck when Clermont's Wales centre Jonathan Davies dropped the ball and halted a menacing Clermont counter-attack in its tracks.
Saracens, with the Vunipola brothers Billy and Mako in powerful running mode, took a 15th-minute lead when Hodgson landed an angled drop-goal to reward an impressive spell of pressure, but Clermont quickly responded through a reminder of their attacking prowess.
Fofana swivelled brilliantly in and out of a tackle near the Saracens posts, and Clermont looked to have sent Napolioni Nalaga over in the corner, despite pressure from Chris Ashton's strong defensive work, but the wing failed to ground the ball in play.
Referee George Clancy consulted the television match official Simon McDowell before the try was ruled out, although no judgement was made on Ashton's tackle, which appeared to be an arms-free hit and potentially illegal.
James then tied things up with a penalty that went over via the post, but Saracens had successfully avoided a first-half surge from Clermont in evidence when they swamped Northampton, and an intriguing semi-final tussle remained firmly in the melting pot.
Hodgson missed a long-range penalty chance 10 minutes before half-time, yet he then bisected Clermont's posts from similar range to nudge last season's beaten European finalists ahead.
Clermont had not remotely threatened to hit the heights of a breathtaking performance against Northampton, but much of that was down to Saracens' defensive resilience and impressive intent to play the game on their terms, and they deservedly trooped off 6-3 ahead at the break.
Clermont, though, responded brilliantly early in the second period, opening up Saracens' defence through a clever James kick that was gathered on the bounce by Fofana, who touched down complete with celebratory dive.
James added the conversion to give Clermont a 10-6 lead, which was arguably rough justice on Saracens, but it gave the French side a head of steam as they began summoning reinforcements from the bench, including scrum-half star Morgan Parra.
Farrell joined the action approaching the final quarter for his first piece of competitive action since January, and Saracens were by no means out of the contest, yet the marginal calls were starting to go against them as Clermont targeted a territorial edge.
Farrell kicked a penalty with 14 minutes remaining to set up an intense finale, but Clermont were not to be denied, and another James penalty six minutes from time sealed the deal.