Rhys Jones, from Stourbridge, won the DHL Rugby Moments that Deliver competition after receiving the highest public vote.
The 13-year-old, who plays centre – or number eight – for Walsall Rugby Club will now deliver the ball for the match between England and France on October 12.
He said: "It was a big shock to me. It was such a high vote, but I'm glad I've won it.
"Everyone around me knows and I'm telling everyone I can.
"I think I'll be nervous because nothing can prepare you for something like that – I'm extremely excited."
Gavin Jones, Rhys' father, said he was "very proud" of his son. "We went down to London to the BT Rugby studios and he was informed he had won and he's off to Japan in October.
"He will be presenting the match ball at Yokohama stadium.
"It was really close. There was over 17,000 votes and he won by four or five per cent. It was right the way and when we turned up we had no idea who had won.
"When it went out, it should be a really good video of Rhys, myself and a coach who was in the room with us.
"One of the presenters said we were going on a tour of the studio.
"We walked out the studios and the presenters were all waiting for us with a crowd of around 250 people.
"It was a fantastic moment.
"I'm very proud of him."
Gavin, 40, originally from Walsall, said previously his son was a "naturally talented" rugby player.
He said: "He has continued to develop very well. I think he's just over 6ft 2 now. He's a big, tall boy. He's not only a big lad, he's quick as well, and he's got all the skills.
"He's very naturally talented rugby player.
"Walsall was my boyhood club. I always played there and that's why my son does. He's followed in my footsteps."