Victorious Japan coach Eddie Jones was delighted to see his side ignore the script and stun two-time champions South Africa in their opening Rugby World Cup Pool B match in Brighton on Saturday.

Japan started the match as 40-1 outsiders but were only trailing by two at the break before they went over for a try in added time to win just their second-ever World Cup match and first for 24 years.

"It's a pretty humbling experience, Japan beating South Africa," Jones told reporters. "I had to look at the score again at the end of the game to see if it was true or not.

"We just kept on hanging in there, hanging in there. At one stage when South Africa went seven ahead you thought they might run away with the game; that would have been the normal scenario. It's like the horror story when a woman goes for a shower at midnight, you know what's going to happen next.

"You might have expected them to score three more tries and win 50-20 and then everyone would say 'well done Japan' at the end because you tried. Today we were more than brave, we stuck at it and the courage at the end to go for the try when we could have gone for three and the draw. It's right up there."

The majority of The Amex was on its feet for the final moments as Karne Hesketh surged over the line to claim victory and Jones was amazed by the reception his players got.

"It was amazing at the end of the game. I think even some Springboks were [cheering] for us at the end. Maybe I'm exaggerating, but the noise for the team was just unbelievable. That has to go down as one of the greatest games in World Cup history.

"This could change the sport of rugby in Japan. Kids will want to be the next (captain) Michael Leitch or Ayumu Goromaru (full-back and top scorer)."

Japan, who host the next World Cup in 2019, next face Scotland in Gloucester on Wednesday.