Leinster Lions will be stepping into the unknown when they meet Perpignan at a packed Lansdowne Road on Sunday, 27 April in their bid to reach their first Heineken Cup final.

Biarritz Olympique fell at Lansdowne Road in the quarter-finals and Irish centre Brian O'Driscoll declared, "It was fantastic playing a club game in front of that crowd and hopefully we'll have that again for the semi-final.

"Biarritz are a fantastic side but I don't really know much about Perpignan. We'll have to analyse what they have done to date in the tournament, but I'm just glad we've got through to the semis. I thought the dream was over in the last few minutes when the Biarritz centre broke through, but Girvan Dempsey came up with a great tackle and we were able to hang on."

Coach Matt Williams added: "Perpignan are a good hard side and they will present a different challenge to Biarritz. Manny Edmonds was very good for them against Llanelli and he's obviously a key player for them.

"I thought the crowd were magnificent at Lansdowne Road but it was hard for us to play the rugby they wanted to see. It really was a new experience for us as a team."

However, Biarritz coach Laurent Rodriguez believes Perpignan can succeed where his side failed.

"We knew how good they were but I thought it would be more difficult for us.

"Brian O'Driscoll was very dangerous but I think Perpignan will be a totally different challenge for them, and I think Leinster could suffer. The Perpignan pack is big and aggressive. The Leinster three-quarters will find it easier than against us today, because our defence was quite good."