Jamie Joseph praised the courage of his Japan players after a momentous 19-12 victory over Ireland on Saturday, saying they had been preparing for the match for three years.
The victory, which is on a par with Japan's famous win over South Africa four years ago, has set the Rugby World Cup alight and put the hosts in pole position to qualify from Pool A. Joseph, who could not suppress a beaming smile throughout his post-match news conference, said his players were more prepared than their opponents.
"The Irish team is a quality rugby side but we have been preparing for this game for a hell of a lot longer than the Irish have," said Joseph, who was installed as Japan boss in 2016. "We have been focusing on today for basically... well the last year at least but probably sub-consciously for the last three years and Ireland have been thinking about it since Monday.
"So we probably had an advantage in that so we just had to execute properly."
Both teams came into the match off the back of victories, Ireland beating Scotland on Sunday two days after Japan had overcome Russia in the World Cup opener.
On Saturday, Japan had none of the nerves they had shown in the first game and, although they were 12-3 down at one stage, Joseph believes the players showed great control to shut out the Irish in the second half.
"All teams go to certain patterns under pressure so when we got ahead, then the Irish tried to take us on physically and I think we were prepared for that," said Joseph.
"The players showed real courage and were able to hold out some tough Irish attacks.
"It is those moments in big games of rugby that win you the game. I am really proud of our boys today."
Japan were relentless in defence, led by lock James Moore who made 23 tackles without missing one, and flanker Pieter Labuschagne, who was captain in the absence of Michael Leitch.
Labuschagne, who has now made a tournament-leading 36 tackles, epitomised the Brave Blossoms' stout defence in the closing stages.
"It was wave after wave coming at us, especially in the second half," said Labuschagne. "It took a special effort from everyone getting back in line, getting back up.
"Everyone knew exactly what they had to do and we just had to go out there and do it. I am really proud of everyone. It was a massive effort."