Iden produced strong performances in the swim and cycle sections, before clocking 2:36:15 on the run to chase down France's Sam Laidlow and clinch victory with an overall time of 7:40:24 on the Big Island.
Periault and Duffy were running shoulder to shoulder but the Frenchwoman pulled away from the Bermudan on the third lap of the run.
While the debate over the political, financial and health implications of holding the Tokyo Olympics in July rages around the world, triple jump gold medal hopeful Will Claye believes a crucial voice is not always being heard - that of the athlete.
Pint-sized 13-year-old Momiji Nishiya took gold in street skateboarding -- new to the Olympics in Tokyo -- while in one of the Games's staple sports a "Terminator" hunted down a dominator to set the swimming pool alight.