The French side are seeking to be crowned kings of European club rugby for an unprecedented third-straight season having won the last two finals in Dublin and Cardiff. Leinster are chasing a fourth title, which would move them level with Toulouse as the most successful side in the history of continental club competition.

But O’Connor knows his squad need to improve on their recent form in the Guinness Pro12, in which they are without a win in their last-four fixtures.

“The fact is we have got to go there and perform very close to our potential to beat Toulon. The lads understand that,” said O'Connor.

“It is a huge challenge for us, they have world class blokes in every position. We need to come up with a plan to go there and get a result.”

Leinster have shown themselves more than capable of overcoming the odds by winning knock-out games on the road in France, picking up a semi-final win at Clermont Auvergne in 2012 and a famous quarter-final triumph against Toulouse in 2006. But they were on the wrong end of the scoreline when they last faced Toulon at the quarter-final stage 12 months ago, losing 21-15 at Stade Felix-Mayol.

“We are massively excited to be going down to play a semi-final. Everyone outside and supporters might be frustrated we are not fulfilling our potential, but it is a difficult thing to do sometimes,” said full-back Rob Kearney.

“We do a huge amount of review work on games. We are unbelievably critical of ourselves and are pin-pointing the things we need to improve on.

“We are not oblivious to the fact there is still a huge amount of things we need to improve on, but we are still very excited by the opportunities available to us.”

Toulon, meanwhile, warmed up for the last four clash with a Top 14 victory over Grenoble, although full-back Leigh Halfpenny picked up a shoulder injury which has made him a doubt for this Sunday’s game.

But back-rower Juan Martin Fernandez Lobbe believes the French champions are well set, saying: “Even though we were under pressure against Grenoble, we remained united and that's the most important thing.

“Everything was there within the side, there was real spirit and commitment and it's nice to enjoy that sort of dynamic when you are building up for an important semi-final.”

Match Facts

• These sides first met in year’s Quarter-final with Toulon becoming the first team since 2010 to beat Leinster in a European knockout game.
• Excluding their meeting last year, these sides combined have lost just two of their last 19 knockout games in the Champions Cup.
• These two sides have won five of the last six Champions Cups between them, including the last four in a row.
• Should they win this match, Toulon will join London Irish (W1, D1) as the only two sides in the Champions Cup to play Leinster more than once without defeat; should Toulon win they would be the only team to play the Irish province more than once while maintaining a 100% winning record.
• Leinster have won three of their last four semi-finals in the Champions Cup, however Toulon have won gone on to reach the final on the two occasions on which they have reached the last four.
• Only Treviso (4.8) have averaged fewer offloads than Leinster this season (5.3), while Toulon have made the most (17.7 per game).
• Leinster have maintained the best ruck success rate (97%) in the competition, though Toulon have forced the worst ruck success rate (89%) from their opponents.
• Opponents of Toulon have won a higher proportion of lineouts (92%) than against any other side this season.
• Toulon have scored nine more tries (13) than Leinster (4) in the first (0-20 mins) and third quarter (40-60 mins) of matches combined this season.
• Leigh Halfpenny has a better goal-kicking success rate (29/35 – 83%) than any other player to kick 20+ successful goals this season, while Ian Madigan has managed the most successful kicks (36/46 – 78%).