France and Britain hogged the Olympic triathlon spotlight as Cassandre Beaugrand delivered a decisive gold for the hosts in the women's race while Alex Yee pipped New Zealand's Hayden Wilde for an amazing victory in the men's event on Wednesday.

Britain's Yee, silver medalist in Tokyo, demonstrating his pacing mastery of the 10km run, overtook a flagging Wilde with less than 400 meters to go in blazing sunshine and 30-degree Celsius heat.

His victory added a 10th Olympic triathlon medal to Britain's collection, after Beth Potter won bronze earlier on Wednesday, cementing the country's dominant spot in the sport that made its Games debut in 2000.

"I honestly thought the race was over for me, but I wanted to give myself that one last chance and not give up," said Yee, who also won mixed relay gold in 2021, after finishing in one hour 43:33, six seconds ahead of Wilde.

The two 26-year-olds, who have been trading podium places on the circuit for years, collapsed after the finish line and Wilde put his arm around Yee.

"It's just great to have a rivalry like this, it makes us stronger, it makes the whole field stronger because Alex is chasing me and I'm chasing him and then everyone else is chasing the both of us," Wilde said.

France's Leo Bergere won bronze, the country's second-ever individual Olympic triathlon medal after Beaugrand's gold, against a scenic backdrop of iconic Parisian landmarks and streets lined with cheering crowds waving flags.

"It’s historic, today French triathlon has achieved something exceptional," said Bergere. "It’s 10 to 15 years of collective work from the staff, the federation, and many athletes."

Originally due to be held on Tuesday, the men's event was postponed due to poor water quality in the River Seine and took place immediately after the women's race, which was no less dramatic.

World number one Beaugrand was in a leading pack of four from the start of the run, then put the hammer down with a kilometer to go to take gold in 1:54:55, leaving Switzerland's Julie Derron and Britain's Potter behind.

Comfortably ahead, Beaugrand sailed serenely through the ribbon, with no sign of the nerves that, she told reporters later, had overwhelmed her to such an extent that she threw up just before the race.

"I was so embarrassed in front of the other athletes, everyone knew I was stressed - it's not the thing you want to do in front of your competition," said Beaugrand, who failed to finish in Tokyo after a bike puncture.

"I told myself 'Cass, you can't go through the same thing as Tokyo again, concentrate, you’ve been doing triathlon your whole life, it’s just another race.'"

Beaugrand and her teammate Emma Lombardi had broken away from the main pack to form a leading four with Derron and Potter after the first of four 2.5km run laps.

Having led the breakaway pack for most of the race, Derron could not match Beaugrand's pace and finished six seconds behind to win silver.

"Running at the front you have no idea what's going on behind you but I feel more comfortable like this," said Beaugrand. "I'm so pleased it paid off."

Bronze winner Potter, who trains with Britain's multi-Olympic medal-winning Brownlee brothers, said: "I'm so happy. I was going for the gold but Cassandre and Julie were just too good for me today."

Lombardi was a frustrated fourth with defending champion Flora Duffy, who has struggled with a knee injury for 18 months, finishing just behind her in what she said was her last Olympics, an impressive fifth appearance for the 36-year-old.

Britain and France will have another chance to shine in the mixed team relay triathlon on Monday, when athletes are set to dive into the Seine once more in teams of four, with France hoping to better their bronze-medal finish from Tokyo.

"We won't hide behind false expectations, we want to win at home," said Bergere, throwing down the gauntlet for the Brits who won gold three years ago.