VIDEO: Libbok v Sexton - the key aspects of the face-off
It is a seasoned and decorated veteran against a young upstart - Ireland legend and captain Jonathan Jeremiah Sexton against Immanuel Libbok.
The cliched response will be that it all starts up front, which it does.
But the face-off between Sexton, 38 and capped 115 times, and Libbok, 26 and capped just 10 times, will be central to the outcome of Saturday's crunch World Cup encounter between Ireland and South Africa in Paris.
The fact that 2019 World Cup winner Handre Pollard has been called up, but not selected for the matchday 23, puts the spotlight even more firmly on the Springbok No.10.
Libbok said it will be an 'awesome' experience to run out at a packed Stade de France - the stadium located just north of Paris in the commune of Saint-Denis.
(WATCH as Springbok flyhalf Manie Libbok speaks about his face-off with Irish legend Johnny Sexton - one of the key aspects of Saturday's World Cup Pool B crunch match in Paris...)
"This, the World Cup, is the biggest stage in the game and I am grateful to be in a position to go out there and represent my country," he said, clearly steering the focus away from the pivotal head-to-head encounter.
"Johnny is a great player and he's done amazing things for Ireland over the years," said Libbok.
"On a personal note, I'm just focussing on myself and preparing as well as I can."
The importance of the game - the world's No.1 team (Ireland) facing off against the global No.2 side (South Africa) for superiority in the pool, has added even more anxiety on the players.
Despite having faced off against many of the Irish players in the United Rugby Championships, Saturday's game is on a different level.
"It is an international and we are playing against the No.1 team in the world, so it's a massive game for myself and us all," the Bok flyhalf said.
"However, I am looking forward to it.
"I've played against a few of their players in the URC, but this is different, it's a Test match, and they'll be at their best, just as we'd like to be," he added.
Libbok admitted that the spotlight has been on the hit-or-miss nature of his goalkicking, but he felt all aspects of his game will come into play in Paris.
"My whole game will be important," he told @rugby365com.
"Kicking at posts, out of hand, be that playing with the ball in hand - my whole game in general.
"I've been working hard on my basic skills.
"A lot of work [goes into] kicking for posts.
"I'm putting a lot of work into getting everything right."
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