Japan backed up last weekend's impressive victory over Wales with a 16-13 success over Pacific Nations Cup leaders Canada on Wednesday.
The loss is Canada's first in the 2013 competition and means that either Fiji or Tonga, who face each other on Sunday, June 23, can win the title.
It was Japan's first win in the five-nation tournament after two defeats.
After full-back James Pritchard scored a penalty in the third minute, neither could score a point with Ayumu Goromaru missing one penalty for Japan and Ciaran Hearn missing another for Canada.
The Japanese, fresh from their historic first victory over Wales last week, repeatedly threatened the Canadians but each time they were pushed back.
Japan finally evened the score after the break when Goromaru cashed in on an easy penalty in front of the Canadian posts in the 45th minute. He added another penalty goal to give Japan a 6-3 lead in the 51st minute.
But their lead was bleak as the visitors connected passes through flanker Nanyak Dala, centre Nick Blevins, scrum-half Sean White before Hearn completed by diving between the posts two minutes later for 8-6 and then 10-6.
Local spectators were delighted when Goromaru touched down in the 62nd minute and he himself converted it for 13-10 before Pritchard evened with a penalty.
Japan again took a 16-13 lead with Goromaru's penalty in the 72nd minute.
On the final day in Tokyo, Fiji will play Tonga and Japan will play the United States.