SAN JOSE, Calif. -- Captain Ayumu Goromaru booted five penalties as Japan opened its Pacific Nations Cup rugby campaign with a 20-6 win over Canada on Saturday.

Samoa topped the United States 21-16 in the second game at San Jose's Avaya Stadium.

Yoshikazu Fujita scored the first game's only try in the 16th minute, touching down after Kotaro Matsushima broke through the Canada defensive line.

Gordon McRorie kicked two penalties for Canada's only points.

Goromaru gave Japan the lead with his first penalty in the eighth minute before Fujita made it 8-0 with his 25th test try. Japan then extended its lead in the second half as Canada conceded more than a dozen penalties.

The win took Japan to the top of the table in the Pacific Nations Cup which began Saturday when Fiji beat Tonga 30-22 in Suva.

Samoa opened a 21-3 halftime lead, then had to hold on during a spirited second-half rally by the United States in a match between teams drawn together in Pool B at his year's World Cup.

Alesana Tuilagi and Ashee Tuala scored tries that stretched Samoa's margin but the United States clawed their way back into the match throughout the second half.

Fiji will play Samoa, Canada plays Tonga and the United States faces Japan in the next round of matches on Friday. The tournament continues until Aug. 3.