Japan won the Asia Rugby Championship on Saturday with a game to spare by beating South Korea 66-10 at Level-5 Stadium.

Following on from their seven straight Asian 5 Nations titles, the Brave Blossoms ensured they will travel to Hong Kong in two weeks assured of the silverware. And they will do so complete with vice captain Ayumu Goromaru, who at one stage could have been contemplating some time on the sidelines.

The fullback marred a good kicking performance — he banged over eight of nine conversions and scored a try — with two dreadful tackles, one of which was spotted by the officials and resulted in a yellow card. Fortunately for the 29-year-old, who was playing in his hometown, the citing officer believed the tackles were not as late and dangerous as first appeared and determined no further action should be taken.

Goromaru's indiscipline aside — he also gifted Jegal Bin South Korea's only try with a dreadful pass — it was a much better performance from Japan, despite the team being in perhaps its worst physical shape in the past three years.

"Today was all about attitude," said head coach Eddie Jones. "I told the players in the build-up that after the first game at the World Cup they will never be at 100 percent again. They need to learn to work through it. Today the team were in their worst physical condition in three years in terms of fatigue, and I am pleased they worked through it. We got a little tired 10 minutes after halftime and gave in to fatigue, but the reserves came on and did their job and lifted things again."

Kenki Fukuoka marked his return to international rugby with a hat-trick of five-pointers as the Brave Blossoms produced a much zippier performance, running in five tries in either half, and limiting their opponents to just the one long-range intercept.

Karne Hesketh had another good game at outside center, scoring twice and setting up a couple of more five-pointers, but as Jones pointed out, it's still difficult to know if he is a real option at 13.

"It's hard to say given the opposition," he said. "He has worked hard on his game and his discipline has improved."

But as the coach pointed out, the Brave Blossoms don't play enough Tier 1 countries to know how good they really are.

"We've played just four Tier 1 nations in the past three years, won 50 percent of the games and were in a position to beat Scotland. We need to keep developing the talent and giving the guys higher level games."

The Koreans for their part, seemed to have come into the game knowing they would lose and wanted to simply do some damage control ahead of their key game with Hong Kong next week, which will determine second spot in the tournament.

"We knew Japan were a level above us and they had much better teamwork than when we last played them. That and their defense made it really difficult for us," said coach Chung Hyung-suk.

Chung then said while Japan was the No. 1 side in Asia, he would like to play the Japanese without the "imports."

However, as Jones pointed out, Ryu Koliniasi Holani, who scored one of Japan's 10 tries, has lived in Japan for more than half his life after coming here on an academic scholarship at the age of 15.

"He knows Japan better than he knows Tonga," quipped the coach.

Fellow Japanese citizen Luke Thompson also got his name on the scoresheet, along with Harumichi Tatekawa and Kensuke Hatakeyama, as the Brave Blossoms made the most of their possession and territory.

"The attitude of the players was very good and we fought it out for the whole game," said Hatakeyama, who led the side in the absence of Michael Leitch. "Considering how intense the training has been, I think we played well and I am proud of our effort."