McGrath ready for duel with dangerous Dupont
With the sparkling record that both sides have in the Champions Cup, it won't come as a shock that Leinster and Toulouse have history.
This season is another chapter in the story of the two most-decorated sides in the competition, with both vying to put that record fifth star on their shirts.
Having already played each other in the pool stage - one home win apiece - they now meet again in the last four, their first knockout clash since the same stage in the 2010/'11 campaign which Leinster won 32-23 at the same venue as this Sunday, Aviva Stadium.
Leinster's 26-year-old scrum-half, Luke McGrath (above), was not involved on that occasion but he's now a pivotal part of the set-up and has his own experience of playing the French giants.
"The two games we have played have been incredibly difficult. The offloading game... they have their flair back," says the Irish international.
"We can't kick loosely to them or their counter-attack will punish us so we're going to have to have a real accurate game-plan and that's something we're focused on."
One player that McGrath views as integral to that is the man expected to line out as his opposite number on Sunday.
Antoine Dupont, who played at out-half in Toulouse's thrilling 47-44 win over Clermont last Sunday, has been in scintillating form in the French club's run to the summit of Top 14 and in their European run.
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"He's such a good attacking threat, he's very strong. He takes on defenders in around the ruck but he also loves going down short sides. He's a typical really impressive French nine.
"We're all going to have to be switched on because he's the focal point of their team. He's an extremely hard player to play against."
As impressive as Dupont has been, and his personal battle with McGrath will have a telling impact on the game, the Leinster man prefers to look at the bigger picture.
"We did well against the whole collective, it's not just him. (Sebastian) Bezy is a brilliant player as well, (Romain) Ntamack as well and (Cheslin) Kolbe from 15 or even as winger, so they've threats all around the park. That's why it's going to be a massive defensive day for us.
"We're going to have to keep the ball for long periods of phases and hopefully tire them down.
"First match, I don't think we respected the ball as much.
"We gave up loose ball and their counter-attack and backs, with flair, just started offloading and offloading and we couldn't slow them down."
That spontaneity that was synonymous with French rugby for so many years had seemed lost until the rejuvenation of Toulouse this season.
Difficulties still exist within their national set-up but free-flowing, quick-thinking rugby has returned in the south.