The last time Johnny Sexton faced the haka in Japan, it did not end well. Ireland's first five-eighths was 16 and the challenge was laid down in the World Rugby invitational youth tournament, to which his school, St Mary's, had been invited.

The boys arrived in Japan at midnight, Sexton recalled. They got up at 7.30am the next day to play their opening match. And they "got absolutely pumped".

"They were probably the best [school] team in New Zealand," Sexton said of Wesley College, the South Auckland school which has produced an incredible number of All Blacks, including one of the greatest of all time in Jonah Lomu.

"There were 35 of us [sleeping] in one room. There were triple bunk beds so you can imagine getting in at midnight was one problem, and then, I suppose, not getting any sleep was the other. The fact that there were 35 of us in one room, with no air con."

Advertisement

It is safe to assume air conditioning will not be a problem ahead of Saturday's quarter-final with New Zealand in Tokyo. Joe Schmidt's attention to detail is legendary and the Ireland head coach will have left nothing to chance as regards preparation for what is being billed as the biggest match in Ireland's history.

Whether the outcome will be any different after the haka has been performed this weekend remains to be seen. But it cannot hurt to have Sexton in a good frame of mind.

Now 34, and in the twilight of his career, Ireland's chances still depend to an unhealthy degree on the Leinster man.

Schmidt's team look an entirely different proposition when Sexton is on the pitch. And he also leads the way off it. He was in fine form yesterday as he began what could be his final week in an Ireland jersey, and his final World Cup game.

Sensibly, Ireland decided to put their main man up early in the week, before the tension ramped up. Even more sensibly, they put him up alongside his old school friend Vinny Hammond, now a high performance analyst for the Irish Rugby Football Union.

Sexton was noticeably more relaxed than at other media sessions during this World Cup. Hammond, a halfback back in the day, was able to joke that he "felt sorry for Conor [Murray]" having spent two seasons playing inside Sexton for St Mary's. And the pair enjoyed swapping war stories about that tour of Japan.

Ireland's Johnny Sexton celebrates after scoring a try during the Rugby World Cup Pool A game at Fukuoka Hakatanomori Stadium between Ireland and Samoa. Photo / AP
Ireland's Johnny Sexton celebrates after scoring a try during the Rugby World Cup Pool A game at Fukuoka Hakatanomori Stadium between Ireland and Samoa. Photo / AP

"We arrived at midnight and I think the next morning at like half seven we kicked off against Wesley College," Hammond said. "So we were facing the haka at half seven in the morning. We got absolutely pumped. It was a disaster."

"I played well," Sexton countered, laughing.

Advertisement

If Sexton can stay relaxed and focused, Ireland's chances of pulling off a third win in as many years against the world champions will increase exponentially.

Sexton is not Ireland's captain but he sets the tone for this squad. He calls the shots. He drives the standards.

With Bundee Aki's three-game suspension confirmed, Ireland needed someone to get their match week off on the front foot and Sexton was that man.

He immediately called out the "negativity" that has been swirling around the squad during this World Cup, describing it as "pretty strange" and saying the group felt "confident" and "positive in how we've been building".

Even if that is just talk — and the criticism of Ireland after their defeat by Japan and their stodgy performance against Russia was entirely justified — it felt significant Sexton should come out on the offensive.

He made a point, too, of saying how different the atmosphere felt compared with four years ago, when Ireland were fatigued physically and emotionally after their bruising encounter with France. Sexton hit the right notes.

"New Zealand or South Africa, for us it was much the same," he shrugged of the fact that Ireland might have avoided New Zealand had they finished top of Pool A. "They pose different challenges but they're both world-class teams and we knew either fixture was going to be really tough. This is the one we've got and we've got to roll with it now."

But it was his final answer that was most telling. Asked whether it was the biggest match of his career, Sexton did not hesitate. "Yeah, it's the biggest," he said. "And the most exciting. You feel it when you wake up this morning and your mind just goes straight to the game. So sleep will probably be a challenge this week.

"But yeah, it's where you want to be as a kid watching. And it's where you want to challenge yourself. I am sure the country will go mad on Saturday morning. I can't wait."