Clermont Auvergne (10) 20
Tries: Malzieu, Floch Cons:Parra 2 Pens: Parra 2
Leinster (10) 13
Try: Horgan Con: Sexton Pen: Sexton 2
Jonathan Sexton was in fine kicking form for Leinster
Leinster salvaged a bonus point to stay top of Heineken Cup Pool Two as they lost to Clermont Auvergne in France.
Shane Horgan crossed for an early try which Jonathan Sexton converted but Julien Malzieu touched down and Morgan Parra converted to level the scores.
Sexton and Parra traded penalties to leave the half-time score 10-10.
Anthony Floch added a second-half try which Parra converted and Sexton and Parra kicked further penalties but Leinster could not make up the deficit.
Leinster began the game brightly and the ball went wide to Sexton from a ruck and he passed to Gordon D'Arcy, who ten looped around the outside and fed Shane Jennings.
Jennings tried to shift it to Isa Nacewa to score but Malzieu palmed the ball away.
The loose ball fell kindly for Horgan, who collected and fell over the line in the second minute.
Sexton converted from wide on the right.
Five minutes later the home side responded when Brock James fed Aurelien Rougerie outside him and then Malzieu, running a sublime angle, came on to a perfect pop pass.
Pace and a sweet angle sent the winger over for a try and Parra converted to level the scores.
Sexton knocked over a penalty from the touchline to nudge Leinster ahead after Clermont were penalised for a hand in the ruck.
Parra replied with a penalty from in front of the posts when Richard Strauss was penalised for failing to release the ball after making the tackle.
The scrum-half's successful kick left the half-time score tied at 10-10.
Floch cut inside Fergus McFadden for the French side's second try in the 53rd minute, with Nacewa's positioning off.
Parra converted to give the hosts a seven-point lead and then Sexton and Parra kicked penalties, before Parra missed with another attempt five minutes before full-time.
In a pulsating, high quality game it was Clermont's ability to retain the ball and grind out the hard yards which proved decisive.
Eoin O'Malley and McFadden were among the best performers for the visitors.
Clermont Auvergne: Floch, Nalaga, Rougerie, Williams, Malzieu, James, Parra, Domingo, Paulo, Scelzo, Jacquet, Privat, Bonnaire, Lapandry, Lauaki.
Replacements: Ledesma for Paulo (69), Faure for Domingo (71), Zirakashvili for Scelzo (41), Pierre for Jacquet (50), Vermeulen for Privat (69).
Not used: Senio, Lavea, Baby.
Leinster: I Nacewa; S Horgan, E O'Malley, G D'Arcy, F McFadden; J Sexton, I Boss; H van der Merwe, R Strauss, M Ross; L Cullen (capt), N Hines; S O'Brien, S Jennings, J Heaslip.
Replacements: C Healy for van der Merwe (66), C Newland for Ross (71), D Ryan for Heaslip (42), E Reddan for Boss (62).
Not used: J Harris-Wright, D Toner, S Berne, D Kearney.