Update: 7:59PM Japan remained unbeaten in the Pacific Nations Cup with a 37-29 victory over the United States on Saturday.
Fullback Ayumu Goromaru registered 17 points, converting all four of Japan's tries and booting three penalties to help the Brave Blossoms secure a bonus-point victory.
Ryu Koliniasi Holani scored two tries while scrumhalf Fumiaki Tanaka and winger Akihito Yamada scored a try apiece.
Blaine Scully scored three of the American's four tries, with Cam Dolan adding another.
Japan, who opened their campaign with a victory in Canada last weekend, now have nine points from two matches.
Fiji opened their title defense earlier Saturday with a bonus point 45-17 victory over Tonga in Suva.
This year the tournament has been split into two conferences for the first time -- Pool A featuring the Pacific island nations of Fiji, Samoa and Tonga, while Pool B comprises Japan, Canada and the United States.
Next weekend, Fiji host Samoa at Suva and the United States play Canada in Sacramento, California.