Leinster 29 Clermont Auvergne 28:European champions Leinster needed a late penalty from outhalf Jonathan Sexton to squeeze past French side Clermont 29-28 and reach the semi-finals of the Heineken Cup after a pulsating game at the RDS tonight.
Sexton delivered the knockout blow in the 73rd minute as an epic contest served up a final quarter full of drama and incident.
Clermont outhalf Brock James missed two glorious chances to set up a semi-final against Toulouse or Stade Franais, who meet on Sunday, when he fluffed a pair of drop goals in front of the posts.
The second failed attempt was the last kick of the game and it concluded a tortuous evening for the hapless Australian, who was off target with five of his nine shots at goal.
In contrast Sexton was almost immaculate with the boot, kicking seven from eight to finish with a 19-point haul test of finishes, but the Ireland number eight was the star of a muscular Leinster back row.
However, in try-scoring terms he was overshadowed by Clermont winger Julien Malzieu who ran in a hat-trick.
Clermont dominated the opening exchanges and powered ahead in the 12th minute through Malzieu.
A chip ahead from James did the initial damage, with Gonzalo Canale gathering before finding Aurelien Rougerie marauding off his wing and he sent Malzieu over for an easy finish.
The conversion was landed by James, who quickly added a penalty, as Clermont continued to create openings almost at will.
Leinster were creaking as they repeatedly fell foul of referee Dave Pearson's whistle and it took them until the 19th minute to escape their own half.
Having finally cast off the shackles, they hauled themselves level with a Sexton penalty beginning the fightback.
Better was to come in the 23rd minute when a piece of magic from Brian O'Driscoll saw the Ireland captain draw Marius Joubert before deceiving Rougerie with a crafty offload to Jamie Heaslip.
Heaslip, who was named man-of-the-match, had support but opted to go it alone by stepping inside back row Julien Bonnaire and crashing over with Sexton converting.
James missed two further penalties and the balance of power shifted when Heaslip crashed over for his second try in the 34th minute.
The Ireland number eight won possession at the lineout and then picked up after a drive from fellow back row Kevin McLaughlin to barge over under the posts.
Sexton converted and then added a penalty to put Leinster 20-10 ahead going into the break, with Morgan Parra squandering a chance to reduce the deficit after Clermont had changed kickers.
Malzieu skinned Shane Horgan to add his second try three minutes into the second half as Clermont clinically worked an overlap after the Leinster's pack tied up.
James missed the conversion but slotted a penalty, leaving a fast-paced match balanced on a knife edge.
Shane Jennings and McLaughlin accumulated hard yards to set up a good field position finished by three points from Sexton.
The tension grew with James finally hitting the target and then Clermont surged ahead, capitalising on two errors from Horgan to send Malzieu over for his third.
First the former Ireland winger failed to gather a long kick and then he saw his clearance charged down by Joubert, who fed Malzieu and the Frenchman danced over.
James hit the conversion but Clermont's hearts were in their mouths as tournament match official Geoff Warren poured over replays of Eoin Reddan attempting to ground the ball over the whitewash, eventually opting against awarding the score.
Sexton kicked another penalty and Leinster's prospects improved when Anthony Floch was sin-binned for a deliberate knock-on as Horgan sought to send Gordon D'Arcy free.
James missed an easy drop goal after Clermont had done all the hard work and Sexton fired his fifth penalty before the match finished with James' wasteful late attempt to seize victory.
Leinster: R Kearney (G Dempsey 77), S Horgan, B O'Driscoll, G D'Arcy, I Nacewa, J Sexton, E Reddan, S Wright, J Fogarty (B Jackman 74), C Van Der Linde (C Healy 41), L Cullen [capt], N Hines, K McLaughlin, S Jennings, J Heaslip Replacements used: C Healy, B Jackman, G Dempsey
ASM Clermont Auvergne: A Floch, A Rougerie [capt], M Joubert, G Canale, J Malzieu, B James, M Parra, T Domingo (V Debaty 75), M Ledesma (B Cabello 75), D Zirakashvili, J Cudmore, T Privat (A Audebert 53), J Bonnaire, A Lapandry (J Pierre 53), E Vermeulen Replacements used: J Pierre, A Audebert, V Debaty, B Cabello
Scorers:
Leinster: Try - J Heaslip (2) ; Conversion - J Sexton (2) ; Penalty - J Sexton (5)
Clermont: Try - J Malzieu (3) ; Conversion - B James (2) ; Penalty - B James (3)
Discipline: Yellow Card - A Floch (69)
HT: 20-10 Attendance: 20,000
Man of the Match: J Heaslip (Leinster)