ASM Clermont Auvergne closed the gap on Leinster to one-point at the top of Pool Two thanks to a 20-13 victory over the Dublin side.

The Top 14 Champions and two-time winners of the European Challenge Cup drew first blood in the crucial back-to-back encounters thanks to the victory. But Leinster hung on to claim a vital losing bonus-point ahead of the return match at the Aviva Stadium next Saturday.

Julien Malzieu and Anthony Floch scored the crucial tries for the hosts in response to Shane Horgan’s try while Morgan Parra and Jonathan Sexton traded the remaining points.

Leinster had entered the game firing on all cylinders and got off to a perfect start when Horgan touched down after just three minutes.

Sexton created the try after making a trademark loop-around and feeding Sean Jennings, the flanker’s pass was slapped down by Clermont but Horgan was able to re-gather the ball and squeeze into the corner, with Sexton converting from the touchline.

But the hosts hit-back five minutes later with a converted try of their own to level the scores. After several drives into the heart of Leinster’s defence the ball was worked wide on the overlap to Aurelien Rougerie who drew his man and put Malzieu over.

Sexton and Parra exchanged penalties with both sides threatening to end the deadlock but defences held strong and the scores remained 10-10 at the interval.

But Clermont broke the stalemate on 53 minutes with Floch’s try. The hosts had attacked the Leinster line with wave after wave of attacks and after several phases Brock James threw a pin-point pass to Napolioni Nalaga who in turn passed to Floch. The French international stepped inside Isa Nacewa and through the covering Gordon D’Arcy and Dom Ryan to score. Parra converted to put the hosts into a 17-10 lead.

Sexton and Parra traded a penalty apiece before Leinster looked to have clawed their way back into the game. After a dazzling piece of footwork by D’Arcy Leinster had several drives at the Clermont line but Jennings made a double movement and the opportunity was lost.

Clermont put the squeeze on Leinster in the final quarter and Parra had the opportunity to starve Leinster of a losing bonus-point but he uncharacteristically hooked a shot at goal on 74 minutes as Leinster hung on for the vital point.