Leinster produced a courageous display in France to earn a valuable bonus point in a 20-13 Heineken Cup Pool 2 defeat to Clermont Auvergne.
Shane Horgan gave the visitors a dream start with a try after only three minutes, but scores from Julien Malzieu and Anthony Floch in either half saw the reigning French champions come from behind to claim victory.
Crucially, though, Morgan Parra missed a late penalty which would have seen the visitors leave with nothing after a bruising encounter at Stade Marcel Michelin.
A cold snap in Ireland meant the former Heineken Cup champions had difficulty training over the past two weeks, but they looked sharp from the outset and stunned Clermont with a well-worked early try.
After some great interplay by Jonathan Sexton and Gordon D'Arcy, a Shane Jennings pass was partially intercepted on the right wing by Malzieu. However, Horgan was still able to recover the ball and finish in the corner. Sexton then kicked a difficult conversion to put Leinster 7-0 ahead.
Clermont responded strongly and fly-half Brock James was almost in for a try soon after the restart. Some desperate Leinster defending only resulted in a temporary reprieve, however, and when Aurelien Rougerie fed Malzieu, he broke Sexton's tackle to snipe over for a try. Parra slotted over to tie the game.
The frenetic start continued with Leinster immediately working their way back into the opposing 22. Their willingness to run the ball at every opportunity was rewarded with a penalty on the left and Sexton struck it over to put them 10-7 in front on 13 minutes.
Parra kicked Clermont level after 25 minutes and Leinster were let off the hook when full-back Floch shot an easy drop goal attempt wide, shortly before the sides went in at the break tied at 10-10.
After a sustained spell of pressure, Floch sidestepped D'Arcy's tackle to find the corner. Parra converted to give Clermont a 17-10 lead.
The sides then traded penalties around the hour mark as Leinster stood firm before Parra missed a penalty with six minutes left that could yet cost his side dearly.