Leinster captain Jamie Heaslip admitted his side made it hard on themselves in claiming back to back victories in the European Rugby Champions Cup as Ian Madigan's seven penalties secured a 21-16 victory over Castres at Stade Pierre Antoine.

Castres prop Saimone Taumoepeau put Leinster on the back foot after five minutes when he scored the game’s only try, but three penalties from Madigan game the visitors a 9-7 half-time lead.

A sluggish start to the second-half was punished as Geoffrey Palis slotted over three penalties after Madigan missed from placed balls just before and after the interval .

Leinster finished far the stronger and with Madigan finding his range again with four successful kicks, moving Matt O’Connor’s side top of Pool Two on eight points ahead of the late kick-off between wasps and Harlequins.

Although admitting relief at securing the four points, Heaslip admitted Leinster missed chances of killing off the game earlier.

“We’re obviously delighted to come to Castres and get the win and go home with the four points in the bag. I probably agree that we didn’t exploit the game, I thought we got momentum at times and broke them down but mistakes kind of killed us and we turned over the ball quite easily to them and we didn’t help ourselves with that.

“The first 15 minutes we kind of compounded a few errors to get them back into the game, gave them a few penalties. But a lot of grit there, it’s a very happy changing room, it’s a tired changing room, but it just shows that when we need to go to that place of really pushing it and grinding it out that we can do it.”

Leinster always expected a tough encounter against a Castres team known for their home displays and Heaslip summed up the frustration of Leinster’s slow start of each half.

“It doesn’t help when we gift them a try and again we gifted them six points or nine points at the start of the second half. Mistakes again killing us, not too dissimilar to last week. The good side of that is that we get a lot of work-ons, but we’re happy with two wins out of two in the first two rounds. We would have taken that, regardless of the score, at the start of the competition.”