In December 1966, Hamazaki was selected the Japan national team for 1966 Asian Games. At this competition, on December 16, he debuted against Singapore. He played 2 games for Japan in 1966. In October 1968, he was selected Japan for 1968 Summer Olympics in Mexico City. Although he did not play in the match, as he was the team's reserve goalkeeper behind Kenzo Yokoyama, Japan won Bronze Medal. In 2018, this team was selected Japan Football Hall of Fame.