SHIZUOKA, 29 Sep - Japan's captain, Michael Leitch, says he cannot separate the win over South Africa four years ago and Saturday's headline-grabbing 19-12 win over Ireland.
"Both are fantastic wins. Last time we went in under no pressure, where no one believed we could win, given Japan team's past record in the tournament and beating South Africa had a big impact on the Japanese rugby," said Leitch, who started on the bench but exerted his influence against Ireland when he replaced Amanaki Mafi after half an hour.
"This time against Ireland, second-ranked team in the world, and under real pressure with all the expectations as hosts from those around us, that must have had a big impact. So if I'm asked which was better, I'd say there's no such difference."
Nullifying the renowned Irish forwards had a huge bearing on the outcome as another Tier 1 nation fell victim to a relentless display by the Brave Blossoms, as happened in the Brighton Miracle four years ago, below.
"The will-to-win, and having the confidence we could win, was the biggest factor. We especially did well at the scrummaging, set pieces and applying the pressure on the ball. As a whole, each of us fulfilled our roles," said the 30-year-old, whose side won all their six scrums.
"We've prepared in the same way as against South Africa (a pre-tournament friendly), eight trying to push back against 10 players, which was something we didn't do before the Russia game. I think the players had the best scrummage practice.
"I was on the 'Irish' side (one of 10) formed by players not starting. It must have been very heavy but they focused on details and that had been a great practice."
Japan's team director, Yuichiro Fujii, said the challenges the players had faced since the last World Cup paid dividends, from playing against all the Tier 1 nations, including two defeats against Ireland in June 2017, and Japan-based franchise the Sunwolves joining Super Rugby from the 2016 season.
"We were outplayed in many areas but also had areas where we could do what we intended. We've accumulated things and began to realise where we can and can't cut it," he said. "Yesterday's result was all built on that."
The electric atmosphere inside a deafening Shizuoka Stadium Ecopa also played a huge role and is something the Japan captain says he will treasure all his life.
"I've played in a few stadiums - won in Brighton against South Africa and also played in Twickenham - but that was the best stadium I've played in my life," Leitch said. "The big stadium packed with red and white jerseys; there were Irish fans, too, and when I heard the Irish anthem I felt the World Cup is wonderful.
"The Japan fans gave us huge cheers whenever we applied pressure, or when we were under pressure, and that must have put quite a pressure on Ireland. I hope we continue to get the support."