Teenage climber Toby Roberts added to Team GB’s medal tally at Paris 2024 with a spectacular gold in the men’s boulder and lead final.

Katarina Johnson-Thompson is also well placed to claim a medal in the heptathlon, but she will have to race an outstanding 800m later on Friday to beat rival Nafissatou Thiam to the gold.

Meanwhile, Hector Pardoe praised Paris 2024 organisers for cleaning up the River Seine after the Briton came sixth in the men’s 10km marathon swim.

Team GB’s women and men made it safely through to Saturday’s 4x400m relay finals, while Max Burgin reached the men’s 800m final.

Breaking, a style of street dance, makes its Olympic debut on Friday with a gold medal up for grabs in the women’s event.

What’s happening and when at Paris 2024

Follow live text coverage of day 14

Full Paris schedule

Paris Olympics medal table

Roberts was in provisional first place when Sorato Anraku, the final climber and favourite, took to the 15-metre wall.

But the world silver medallist from Japan, who only had to match the Briton, lost his grip and slipped near the top to hand Roberts a dramatic gold.

The 19-year-old, who improved his climbing on a DIY wall built in his dad’s garden, had scored 92.1 points in the lead final to take his total to 155.2 – 9.8 points ahead of Anraku in silver.

“I am just lost for words. To find out that I had got the gold in that moment was truly incredible,” Roberts told BBC Sport.

“I have been training for this moment my whole life. To say it hasn’t sunk in is an understatement. I imagine later it will be a flood of emotions.”

Johnson-Thompson headed into Friday with a narrow lead of 48 points over long-term rival Thiam, thanks to season’s-best performances in the 100m hurdles and high jump, and a personal-best in the shot put.

The 31-year-old conceded just three points from her lead in the long jump when the Belgian registered a jump one centimetre further.

However, Thiam’s superb performance in the javelin, one of Johnson-Thompson’s weaker events, hurled her to the top of the standings with 5,942 points.

The two-time reigning Olympic champion’s throw of 54.04m overshadowed Johnson-Thompson’s season’s best of 45.49m.

Thiam will go into the final event, the 800m at 19:25 BST, with a lead of 121 points, meaning the Briton, who has never won an Olympic medal, needs to run around eight seconds faster to have a shot at the gold.

With pre-Games medal favourite Jake Wightman out with a hamstring injury, it looked like Team GB would be without a representative in the men’s 800m final after Ben Pattison and Elliot Giles failed to qualify.

However, Burgin, going in the last semi-final, pulled off a personal best of one minute 43.50 seconds to finish third and go through as one of the two next fastest.

“I don’t really know what to say. It sort of came out of nowhere,” said 22-year-old Burgin. “I wouldn’t have believed it a month ago, I wouldn’t have believed it a few weeks ago.”

In the women’s 4x400m relay, Team GB’s Laviai Nielson battled down the home straight to cross the line in second in three minutes 24.72 seconds to qualify for Saturday’s final.

Meanwhile, in the men’s event, Charles Dobson held off a late charge by the United States’ Chris Bailey, who had a strong anchor leg to finish third after 16-year-old Quincy Wilson struggled in the opening lap.

There was disappointment for GB’s Cindy Sember, who crashed on to the track floor in her women’s 100m hurdles semi-final after clipping a barrier with her trailing leg.

Britain’s Hector Pardoe praised Paris 2024 organisers’ attempts to clean the River Seine and setting a “good precedent for the rest of European nations to clean up the rivers”.

Kristof Rasovszky of Hungary upgraded his silver from Tokyo and was joined on the men’s 10km open water swimming podium by compatriot David Betlehem, who took bronze, while Germany’s Oliver Klemet won silver.

The water quality of the Seine has been a major talking point before and during Paris 2024, with the men’s triathlon postponed by a day and several familiarisation training sessions cancelled because of the low water quality.

“There was a lot of negativity about the Seine before the Olympics. At least they have tried; they have spent £1.2bn on this clean-up project so bravo to them for doing it,” Pardoe said.

“Imagine if we can get swimmers swimming in the Thames, that would be an amazing experience. That shows why sport is such a good thing for change, we can get things done with sport.”

Breaking, the Olympics’ latest foray into urban sports as it hopes to engage younger audiences, gets under way at Place de la Concorde, with the women’s b-girls competition starting at 15:00 BST.

The style of street dance, which originated in 1970s New York, is characterised by acrobatic movements, speedy footwork and a hip-hop soundtrack.

With breaking left off the programme for LA 2028, it is a rare chance for the dancers to perform on the Olympic stage.

Dancers will compete in one-on-one battles consisting of two 60-second throw downs (three in the knockout phase). Nine judges vote at the end of each battle to decide the winner.

The b-girls and b-boys will receive marks for technique, vocabulary (the variety of moves incorporated), execution, musicality and originality.

No British breakers will compete at the Olympics with b-boy Kid Karam, b-boy Sunni and b-boy Sheku all finishing outside the qualification spots at the Olympic Qualifier Series earlier this year.