The 27-year-old was cheered on by thousands of fans and collapsed to the floor after crossing the line in 1:54:55.
“It was the longest 1500m of my life, but I never doubted at the end,” a jubilant Beaugrand told Olympics.com. “I didn’t realise that I was Olympic champion, I shouted but I told myself that it wasn’t possible, I told myself that someone had to wake me up!”
Derron, who had led for most of the final stages, clocked 1:55:01, while pre-race favourite Potter finished nine seconds back.
"It's incredible! It was such a great course, great race, and I'm just so pleased to walk away with (an Olympic) medal,” Derron said. "It hasn't sunk in yet to be honest!"
Derron won silver in the mixed relay at the world championships earlier this year and admitted she was motivated by the home crowd cheering on her rival.
"It was crazy on the run because I couldn't hear anything because the crowd was so loud! They were cheering for everyone, of course I heard more French cheers, but that just made me go harder to make sure I was also on that podium."
Team GB's Potter competed in the 10,000m at Rio 2016 and made history in Paris by becoming the first Olympic athlete to compete in both events.
"I'm really happy. I think it was an all-round solid performance and I'm really happy to come away with the bronze," she said. "There was a lot of pressure coming in (to Paris 2024), and I would have loved a gold medal but it wasn't to be. I feel like I gave it everything, I committed to the race and I tried to go for it.
“The crowd was amazing, the support was amazing, and I happened to catch a few of my friends and family in the crowd as well which really boosted me."
Julie Derron of Team Switzerland celebrates winning the silver medal
This was triathlon Paris 2024 style, as much a sight for the eyes of spectators as a spectacular competition for the athletes.
The race began with Tokyo 2020 Bermuda’s Flora Duffy pushing to the front as she navigated the choppy waters of the Seine, ending the swimming leg some 17 seconds ahead of the chasing group.
But this wasn’t going to be a race with a runaway winner.
Not long after clambering onto their bike, a group of 10 formed at the front, including two home favourites, Beaugrand and Emma Lombardi.
As the athletes wound their way around the 40km cycling course, the rain that had settled onto the cobbled streets began to play its part. Multiple riders fell as they navigated the Champs Elysees. One of the world’s most iconic avenues proving today to also be one of its most treacherous.
As the crowd roared their approval across the avenues and bridges of central Paris, a fascinating race began to unfold.
By the closing stages of the run, only four athletes remained in contention, with just three medals on offer.
Duffy, so strong in Tokyo, fell back to fifth, Georgia Taylor-Brown, Britain’s silver medallist in Japan, dropped behind even further.
With Potter, Lombardi and Derron all chasing gold on the final lap of the run, Beaugrand made her move, kicking hard for the finish line that stood overlooking the Eiffel Tower on the famous Pont Alexander II bridge that crosses the river Seine.
As she passed through the tape, the crowd roared their support for another French champion at these Paris Games.
