Watch: Bonkers Japanese game-show pits shot putter Tom Walsh vs All Black Nepo Laulala in epic test of strength

How exactly this came to be is unclear, but a bizarre Japanese game show has pitted Kiwi Olympic shot putter Tom Walsh against All Blacks prop Nepo Laulala in a feat of strength called The Power Wall.

With a dramatic initial face-off supported by a huge pyrotechnic display of shooting flames, the two athletes talked a little trash before the battle began.

Walsh and Laulala were the finalists from a list of a list of high-profile athletes including US Olympic sprinter Justin Gatlin and Russian gymnast Denis Ablyazin.

"Every boy in New Zealand wants to play for the All Blacks growing up, I did myself as well. He's going to be tough to beat but I think I can take it out," Walsh said ahead of battle.

Laulala was a little less complimentary before the contest.

"Ah, the medal's not going to help him win," Laulala laughed, referring to Walsh's bronze medal at the Rio Olympics.

The game itself is fairly basic after all the build up.

A barrier, The Power Wall, is placed between the contestants and the first to push it all the way to their opponent's end is the winner.

Laulala's experience in the scrum was telling, as he overcame his rival to claim the prize.