The competition's dominant nation recorded a 39-9 victory over their South Korean opponents in the Pool A clash at the Saitama Memorial Gymnasium in the Japanese city.

In the other match in the group, Macau - whose arrival at the event was delayed owing to a typhoon affecting their flight - overcame debutants the Philippines 25-4.

The game was initially due to be the first match of the tournament but was rescheduled because of Macau's late arrival.

In Pool B, Japan edged New Zealand 10-9 in a thrilling contest, while Hong Kong dispatched Indonesia 25-3.

Only one team from each group will fail to make it through to the knock-out rounds, with the other eight teams all progressing to the quarter-finals.

Once the knock-out stages begin, if a match is ever drawn at full time, a 10-minute period of overtime will be played with the golden goal rule applying.

If following that, the game is still tied, penalties will be taken.

The competition is scheduled to end with finals day on August 5.