It was one hell of a statement of intent and Luke Thompson was still intent on putting his stamp on this historic day a good hour after the final whistle when someone made the mistake of suggesting that Ireland had been 'well on top' at the end of that first quarter.

(Guilty, your honour).

“Aw, I'd debate that now, that they were well on top,” said the veteran lock who has been living and playing in Japan for 16 years now. “I think they scored two tries from kicks but if you are asking if they were well on top, then it's not true at all.”

Thompson has been playing test rugby for the Cherry Blossoms since 2007. He played in the first of his four World Cups that year when Japan shipped 91 points to Australia and 72 to Wales. The high point then was a 12-12 draw with Canada in Bordeaux.

Different times.

The 2015 tournament, when they saw off the Springboks and won two other games, showed exactly how far they had come, and what latent potential there was in the game here, and yet Thompson wasn't exactly happy with the vibes he was picking up prior to this one.

“South Africa was amazing and this was truly amazing as well. Everyone had written us off. All the Irish media were talking about South Africa and how they are going to play them in the quarter finals and what they have to do. So we know what we have to do. It's a very special moment.”

So he'll enjoy this. Michael Leitch was more po-faced afterwards. The celebrations started and ended in the dressing-room, he said. Thompson will allow himself a beer or two tonight though. Days like these are the reason you play the game, he said. He's right.

But there was no giddiness, no wide-eyed disbelief at what had just happened.

Ireland scored 12 tries across two tests against Japan here in the summer of 2017. They did it without their best players who were on British and Irish Lions duties in New Zealand at the time but Thompson's thoughts on this game were remarkably matter-of-fact.

Why did they win? They prepared well, knew their game better and are better athletes now than then. They won, he said, because they didn't let Ireland do what they wanted to do. They won because they did what they wanted to do. Who says rugby is a complicated game?

The estimated TV audience for their tournament opener against Russia last Friday week was 40 million people. That's about a third of the total population. God knows what it must have been by the time the final whistle went here and yet Japan played like a side devoid of any pressure.

They played with a fast and open and fluid style that only adds lustre to this win. They have legitimised the calculated gamble that was World Rugby's decision to hold this tournament in the Far East in one brilliant 80-minute performance.

The tournament is already a massive success because of this but that's in a wider sense. Japan's journey as a team is far from over and the memories of 2015, when they shocked the world with the Miracle of Brighton but fell at the pool stages despite three wins, has not been forgotten.

“We've got a goal to make the top eight and we're not there yet,” said Thompson. “We know that 2015 we won three games and still missed out. That hangs in the background but we are a new team and we still know the challenges we have.

“We have two really good teams to play still and tonight shows you if you are not 100% on your game you can lose to anyone. We have to go back out in seven days time and put in an excellent performance against Samoa. That's what we focus on for now.”

And to think that he could have missed all this.

Thompson retired from international rugby after that 2015 tournament in England but the itch to do it all again was impossible to ignore and, after answering an SOS to lend a hand for a game against Ireland in 2017, he returned full-time this past summer.

It was for nights like this that he came back.

“Playing in a World Cup and beating the No.1 team in the world, that's what dreams are made of.”