Japan captain Michael Leitch insists the shocks are not over yet as he set his sights on Scotland.
The Brave Blossoms on Saturday pulled off the greatest upset in Rugby World Cup history when Karne Hesketh's last-gasp try secure a remarkable 34-32 win over mighty South Africa in Brighton.
But New Zealand-born Leitch insists the win was no fluke as the build-up begins to their meeting with the Scots in Gloucester on Wednesday.
"We've been training to beat the Springboks for three years so we are pleased with that effort," he said.
"It's our first World Cup win in 24 years and to beat Springboks is pretty amazing, but now we have Scotland around the corner so we will focus on that."
Japan's stunning victory, set up by tries from Leitch and Ayumu Goromaru, whose nerveless penalties kept them in touch in the second half before Hesketh's heroics, has left Pool B wide open.
And their Australian coach Eddie Jones has also promised that the Asian champions are far from finished yet.
"We're not done - we're here to make the quarter-finals," he said.
"Then I'll retire and go on television like Sir Clive Woodward!
"I'm too old for this, at 55, I should be in Barbados watching the cricket. But the history has now changed for Japanese rugby."
South Africa managed four tries, through Francois Louw, Bismarck Du Plessis, Lood De Jager and Adriaan Strauss.
But they are now licking their wounds ahead of what promises to be a bruising encounter with Samoa at Villa Park on Saturday.
"It was one of those performances where we can't put our finger on why we lost, we were just beaten by the better team on the day," admitted captain Jean De Villiers.
"It was a fantastic day for Japan but we can't make any excuses. It's not going to get easier against Samoa and as players we need to take responsibility."
Australia coach Michael Cheika paid tribute to Japan following their Springboks heroics.
Speaking at a Wallabies press conference in Bath on Sunday, Cheika said: "I think it shows the great values that people have to have.
"You've always got to have that readiness in rugby because it's a contact sport.
"It's a game where the humble usually succeed, you know what I mean? In any one contest, you might go good in one scrum and then you might get pushed off in the next one.
"You've just got to be on all the time.
"I think that all the teams who are coming here now more often - from what I've seen over the progression of the tournament - are believing that they can win, as opposed to coming here just to participate.
"I was speaking to (Eddie Jones) at the coaches' thing with the referees the other day. He did seem to have a lot of belief.
"They've had excellent preparation, obviously, and it is very deserved for a guy who has put a lot into the game over there.
"He will be happy, but he will be thinking already about the next game, which is coming upon them quickly, and trying to navigate a course through to the quarter-finals."