We've come back from worse situations than this and we can again -- Sexton
Munster versus Leinster. In many ways it is the fixture that has defined Jonathan Sexton.
And one that has produced its own stirring narrative.
Not only does it chart a team's ascension to European greatness, it also reflects the intense internecine rivalry of the respective teams through the prism of his personal joust with Ronan O'Gara for national pre-eminence.
From impressionable youngster to the international class star that he is today, Sexton has regularly stamped his authority on the most pivotal date in the Irish rugby calendar.
It hasn't always been smooth sailing; the teams' special rivalry does not allow for any great period of untrammelled superiority. But it has undoubtedly shaped Sexton's career.
"I've never really thought about it like that," muses this son of Kerry stock, who has many more relations scattered across Munster.
"I've had a lot of really big games against them, my first one, my first big European game.
"A lot of big battles since then. They're special. I always get texts from uncles saying 'I hope you play well, score a bagful of points, get man of the match and lose!'
Tossed unprepared into the lion's den that was Thomond Park during the Christmas period of 2006/07, Sexton learned a harsh lesson in the footprints of a maestro on his full debut, as Ronan O'Gara guided the then European champions to victory.
"It was a strange day," he recalls of the circumstances surrounding the 25-11 defeat.
"I got told early in the week that I'd be playing. It was a long old week, waiting for it.
"I think my whole family travelled down for it, about 20 of them. It was a big occasion for them too, a lot of them are from Munster. I think they got a fair bit of stick!"
A year later though, the nascent out-half bristled with purpose on a wretched night in Cork that signposted his side's intentions to become European champions.
That ambition was franked with a command performance at Croke Park in 2009, as Leinster were scaling the European mountain upon which Munster were sliding backwards.
His primal scream at a defeated and deflated O'Gara that day remains one of Irish rugby's most powerful images.
He subsequently apologised for letting his emotions run riot but such is the nature of this often intoxicating fixture.
Tomorrow, Sexton renews combat against the men in red.
And also with his old nemesis, O'Gara, with whom a rivalry has developed that has accelerated in intensity amongst media and supporters, even if Sexton himself remains slightly amused at how people can alight on an individual battle in a team sport.
"It's not about me versus Ronan O'Gara," he demurs softly. "It's Leinster versus Munster.
"There are so many other things going on around you. Often it's very unfair to compare player against player after a game because one pack is on top and there are so many things that you rely on.
"So I've never really looked at it as a one-on-one battle."
Croke Park, the truly seminal 25-6 success, confirmed Sexton's ability and his composure -- his first task as replacement was to nervelessly convert a difficult penalty.
A Heineken Cup coronation followed and, soon enough, he would supplant the man he once venerated as Ireland's number one.
"Obviously, I was young at the time," the 27-year-old recalls of his initial experiences of lining up against O'Gara.
"I looked up to him for many years before, he was the Irish out-half then and had a lot of success with Munster at that stage. So it was pretty strange being on the same pitch as him then.
"Now, I've played a lot against him, with him, trained with him and it won't be as strange."
The motivation remains the same. To win. Particularly now that his team are struggling. A defiant gesture is demanded from a fixture already freighted with significance in so many ways.
"We've come back from worse situations than this before," he says. "When Joe Schmidt first came in, we lost four of our first five games. That was a pretty tough place to be.
"People were calling for his head. People were saying the players were not performing. But we bounced back then and the next few weeks can define our season."