Keely Hodgkinson punched the air as she confirmed herself as the poster girl of British athletics with a stunning win in the women’s 800m final, as Team GB’s velodrome campaign kicked off with a world-record gold medal run.

Hodgkinson, at the age of 22 already the world No 1, took an early lead in the Stade de France but Kenya’s Mary Moraa and Ethiopia’s Tsige Duguma stubbornly stuck to her right shoulder throughout the first lap.

It was only in the final stretch of the last leg of the biggest race of Hodgkinson’s career that the British middle-distance runner pulled away, stretching her opponents’ ability to keep up with each long stride. Hodgkinson, from Atherton in Greater Manchester, punched the air as she flew through the finish line, posting a time of 1min 56.72sec.

Duguma ran a personal best of 1.57.15 but it was simply not good enough against Hodgkinson, whose Paris gold joins three European titles and silver medals at the Olympics, world championships and the Commonwealth Games. Moraa, the world champion, took bronze.

With her imperious run, Hodgkinson became the first British woman to win an Olympic 800m title since Kelly Holmes in Athens 20 years ago – when Hodgkinson was two years old.

“I’ve worked so hard over the last year and you could see how much it meant to me as I crossed the line,” Hodgkinson said. “I can’t believe I’ve finally done it. It means so much to me. And to do it here, where better? The audience was absolutely incredible, it felt like a home crowd to me. So I’m super happy.

“I trusted myself, I could feel Mary [Moraa] coming at me down the back straight. But I showed composure and I got to the line first this time. I had a cheeky look at the screen just to make sure but you can’t do anything until you cross that line.

“I’m now the Olympic champion for the next four years and nobody can take that away from me.”

The thrilling triumph followed an unimprovable start to the start of the women’s campaign in the track cycling. Katy Marchant, Sophie Capewell and Emma Finucane twice broke the world record in the qualifying rounds at the Saint-Quentin-en-Yvelines Velodrome and went even faster in the final, posting a time of 45.186, to beat New Zealand by five-tenths of a second.

It was Britain’s first medal in an event in which they have failed to even qualify at the past two Games.

Finucane, who has been billed as a successor to Victoria Pendleton and Laura Kenny as the British queen of the velodrome, said: “We have been working really hard on this. Process for us is really key and we nailed that final.”

Triumph on the track had followed a glorious five-minute patch in the Vaires-sur-Marne Nautical Stadium a few hours earlier when Joe Clarke and Kimberley Woods emerged from the chaos of the men’s and women’s canoe slalom with silver and bronze medals, respectively.

Woods said: “Two medals in Team GB in five or 10 minutes is pretty incredible. I’m really proud that I came away with another bronze medal.”

Clarke, an Olympic gold medallist in 2016, watched his dream of repeating past glories die when he was barged off the ramp in the men’s race by his German rival Noah Hegge but fought back to take second place behind New Zealand’s Finn Butcher.

“I’ll be honest with you,” Clarke said, “I came into this event wanting to win gold and that didn’t happen today but I’m not disappointed in any way.”

He said that Hugo, his one-year-old son, had been wearing a supporters T-shirt on every race day bearing his face. “He picks it up in the morning and says ‘dada’ and hugs it,” Clarke said. “It’s the cutest you’ll ever see. I’m very proud to have him here as he’s my absolute world and I can’t wait for some family time with my wife and son now.”

There was also a bronze in the mixed triathlon for Team GB’s Alex Yee, Georgia Taylor-Brown, Sam Dickinson and Beth Potter, although it had looked for a short while like it might be a silver. Three teams were slugging it out as they approached the finish line of the final run section on the Pont Alexandre III but Laura Lindemann of Germany sealed gold.

Taylor Knibb of the USA and Potter came in a second behind in a photo-finish, and organisers initially awarded Britain second place but it was reversed shortly before the medal ceremony. Potter said: “The run leg was tough, I think I was a bit tired from the bike. I thought we might have had the silver, but we got a bronze. Still a medal.”

There will be no British representation in the women’s final after the favourite for gold, Molly Caudery, 24, and the Tokyo bronze medallist, Holly Bradshaw, failed to hit their usual standards.

Bradshaw was devastated to miss out and had been consoled by Caudery as her fourth and final Olympics came to a close. “I’m just crushed,” she said. “I knew this was going to be my last champs. I’ve only got a few competitions left, so I am heartbroken.”

Caudery, the reigning world indoor champion, had been the only competitor to elect to skip the 4.40m height attempt, choosing to enter at 4.55m, but she was unable to clear the bar.

It emerged that 4.40m was all that it would take to advance leaving Caudery devastated but she defended the decision. “When I have been jumping 4.80 and 4.90 all year round, 4.55 shouldn’t have been a problem,” she said. “It is just a really unfortunate day.”

There was also a bittersweet afternoon in the Bercy Arena as the US superstar gymnast Simone Biles picked up the 11th Olympic medal of her career but not the gold that her Games story of redemption had demanded.

Biles, who had to pull out of events at Tokyo after suffering from the “twisties” – a condition where she felt unable to carry out moves she had once found easy – was pipped by her Brazilian rival Rebeca Andrade for the gold by 0.033 points in the floor exercise final.

The 27-year-old, the most decorated women’s gymnast and the oldest American woman to make an Olympic gymnastics team since the 1950s, said she felt no disappointment at taking her fourth medal in Paris following gold in the team event, the all-around and the vault. A fall on the balance beam had left Biles with a fifth-place finish in that event. “I can’t be more proud of how I’ve done,” she said.