The 33-year-old, making her fourth appearance at an Olympics, came out on top of the 56-woman field with a time of one hour 55 minutes 36 seconds – more than a minute ahead of Great Britain’s Georgia Taylor-Brown and USA’s Katie Zaferes.
Bermuda already held the record for being the least populated country to win a summer Olympic medal thanks to a bronze for boxer Clarence Hill in 1976 but now they have their first gold medal winner.
“It’s been a heck of a lot of pressure for five years,” said Duffy.
“I would never recommend being an Olympic favourite for five years. Of course, it’s made it all worth it now.
“I think the whole of Bermuda is going crazy. That’s what makes it so special to me is that, yes, this was my dream, but I also knew it was bigger than me.”
Duffy, who rejected the chance to represent Britain as a teenager, is already familiar with writing her name into the history books having become Bermuda’s first female Commonwealth Games champion in 2018.
She added: “I’m just proud I could be Bermuda’s first gold medallist, first female medallist, and hopefully inspire everyone back home that this is possible.”
To put into context the size of Duffy’s win, at 51 kilometres the triathlon event itself is longer than an end-to-end walk across the length of Bermuda (40km). It is 15 times smaller than New York.
Overnight rain in Tokyo had delayed the start by 15 minutes because of slippery conditions but once it got under way Duffy took control after the first four laps and never looked back.
A huge smile turned to tears of joy as she crossed the finish line as the realisation of what she had achieved sank in.
“I tried to just keep my composure and not allow my mind to drift to the fact that this was really happening until about the last kilometre of the run,” said Duffy.
“I saw my husband, he’s my coach, on the side of the road, and just gave him a little smile.
“From there I just sort of allowed all the emotions to come but I truly don’t think it’ll hit me until a couple of days from now.”