Leinster and Toulouse clash in the Heineken Cup for the ninth time in the sell-out semi-final at the Aviva Stadium on Saturday – and the third time they have met in the knock-out stages in the last six tournaments – with defending champions Toulouse 5-3 ahead in wins.

Last season Toulouse ended Leinster’s hopes of making a successful defence of European club rugby’s most coveted title when they won 26-16 at Le Stadium at the semi-final stage on the way to their fourth Heineken Cup crown.

This time the French club are the ones who have to travel with the winner meeting either Northampton Saints or Perpignan in the 16th Heineken Cup final at the Millennium Stadium three weeks later.

“We know each other pretty well after all those times we have played them in the Heineken Cup,” said Irish international prop Cian Healy, a try scorer in the 20-8 away win over Aironi at the weekend that cemented their second place in the Magners League.

“Potentially this could be our final game in the Heineken Cup this season so it will be a clear case of ‘do or die,’ there can be no holding back.”

The two teams have had some classic encounters – with perhaps Leinster’s sensational 41-35 quarter-final win at Toulouse in 2006 the pick of the lot.

“I was still at school when that one was played, in fact it was the year that I was in the Belvedere College side that won the Schools Senior Cup,” said 23-year-old Healy.

“I did play in last season’s semi-final against them over in France and, while it is always great and enjoyable to play in those important games, you cannot enjoy it if you walk off without the win and we walked off without the win that would have put us in the final.”

Healy has featured in Leinster’s last 27 Heineken Cup matches since making his tournament debut in the Round 4 match against Edinburgh in December, 2008, and will relish returning to the Aviva Stadium after scoring two tries in the Pool 2 fixture against ASM Clermont Auvergne just over four months ago and being a key part of the team who beat Leicester Tigers 17-10 in the quarter-finals at the home of Irish rugby earlier this month.

“It is great to be going back the Aviva, we are turning it into a type of fortress, and the support we get there from the Leinster fans is unbelievable,” he said.

“They are there for us every game, big or small, and it will be great to have them behind us for the semi-final.

“The semi-final is an enormous game for us. We certainly know Toulouse are very strong up front, are a well drilled side and have quality throughout but we will focus on what we can and must do and not on what they can do.

“This will be our fifth match against French opposition this season as we played Clermont and Racing Metro in the group stages and those games confirmed that part of the way French clubs play can be their unpredictability and how they can come up with different ways to play and win.

“We are playing well and putting few things together and, while there are also a few things to work on, we feel we are going in the right direction under Joe (Schmidt) who is certainly getting the best out of the players.”

Toulouse No 8 Shaun Sowerby relishing the prospect of going head-to-head with the Irish province’s star-studded international back row.

The former South African international, who has made 42 tournament appearances and is a 2010 Heineken Cup winner with Toulouse, believes the four times European champions face a massive challenge in their bid to qualify for a seventh final.

“In my opinion there are only a couple of teams in Europe that you could class as a complete side – and Leinster are one of those teams,” said the Springbok powerhouse.

“They have a good pack that can dominate, talent out wide, and the experience and the know-how to win games.

“They are a big European side who have represented themselves well this season, as they have done over the last couple of years.

“We all saw their quarter-final win against Leicester Tigers, it is on all of the computers down at the training ground, and now we will sit down and fully focus on the match and on Leinster.

“I thought they played really well and deserved the win – it really was a big statement beating Leicester.

“However, Leicester were unlucky in the game because they did have chances and opportunities to take the game but didn’t, so they will be disappointed.”

Toulouse and Leinster know each other well, the French giants 5-3 ahead from their eight meetings, including a 26-16 semi-final win at Le Stadium a year ago, and Sowerby is wary of home advantage tipping the balance again.

“We are extremely familiar with them, we have met them a lot over the last few seasons so we know what they are all about,” said Sowerby. “They are technically spot on, they play with pace and intensity and we have to be ready for that.

“Home advantage is huge at this stage and of course the fans will all be right behind Leinster but as the away side we will have to thrive off the atmosphere and make the best out of it.

“I have never been to the Aviva but from what I have seen I’m expecting a big stadium with a great atmosphere.

“The matches that have been played there look great so I’m sure this match will be another great occasion.

“You look forward to playing in a stadium when there are 50,000 plus supporters screaming, whoever they are supporting. It just adds to the event and the occasion and lifts everybody.

“Obviously we beat them at the same stage last year but that was on home soil and home advantage in this competition is huge and we are really up against it in Dublin, it’s a huge game and a huge test for us.

“No-one is looking any further than the semi-final stage, we have got a massive obstacle to overcome in Leinster and that is our focus in the tournament. If we manage to get the victory then we will turn our attention to defending the title.

“Biarritz are a top team, they do not always play the prettiest of rugby but they certainly know how to win games. We played well at the start of the quarter-finals but fell off the pace in the second half, though to come through the game was fantastic.”