Triumphs in sailing and showjumping took Team GB’s gold medal tally to 15 on Wednesday as Katarina Johnson-Thompson suffered a heart-breaking injury to end her Tokyo medal hopes.

Ben Maher won individual showjumping gold after eclipsing his rivals aboard the brilliant Explosion W, taking Great Britain up to fourth in the overall medals table.

It comes as Hannah Mills became the most successful female Olympic sailor in history after claiming gold with Eilidh McIntyre in the women’s 470 class, while 13-year-old Sky Brown entered the record books with her skateboarding bronze.

But there was devastation alongside the elation when world champion Johnson-Thompson pulled out of the heptathlon after suffering an injury to her right calf in the 200m.

The 28-year-old refused treatment and a wheelchair on the track to pick herself up and finish the race, limping over the line, but was disqualified for leaving her lane after falling.

Elsewhere, Brown’s bronze in the women’s skateboard park event at the Ariake Urban Arena aged only 13 made her Great Britain’s youngest Olympic medallist.

Maher produced a dazzling display under the floodlights to give Team GB its second successive Olympic showjumping champion, following Nick Skelton’s success with Big Star in Rio five years ago.

Mills and McIntyre have dominated the regatta at Enoshima, winning two races and only twice finishing outside the top four, and they went into the medal race with a 14-point lead.

They only needed to finish in the top seven to clinch gold and they were never in any danger, crossing the line comfortably in fifth.

Mills, who was one of Team GB’s flag bearers at the opening ceremony for the Games, won silver in London and gold in Rio with Saskia Clark in the same boat.

Her mother Fiona Mills said she experienced a “mixture of emotions” when a protest from France was lodged in the race but later dismissed, confirming a gold for the pair.

Speaking at Cardiff Bay Yacht Club, Mrs Mills said her daughter had worked “so hard” throughout her sailing career and is now inspiring young sailors.

“She’s always wanted to do it, she’s always loved it – I’ve never, ever had to force her to go and train or go to a competition, because she’s just loved it,” she said.

McIntyre’s fiance Jonny Forer, from Old Portsmouth, added: “It’s absolutely amazing, it’s such a moment for her, it’s always been her dream. I’m so proud of her.”

The victory continued a hugely successful two days for Britain’s sailors, with Mills and McIntyre making it three gold medals after success for Dylan Fletcher and Stuart Bithell in the 49er and Giles Scott in the Finn on Tuesday.

It is the country’s second best Olympic tally after Beijing in 2008, when they won six medals, including four golds.

Mills joined forces with 27-year-old McIntyre when Clark retired following the Rio Olympics and the pair marked themselves out as the ones to beat by winning the world championships at Enoshima in 2019.

It is a debut Olympic medal for McIntyre, who follows in the footsteps of her father Mike – the gold medallist in the Star class at the Seoul Games in 1988.

Her father, who watched her win from Hayling Island Sailing Club in Hampshire, explained that his own gold medal had helped motivate his daughter in her sporting career.

Mr McIntyre told the PA news agency: “It sits in a little golden cabinet outside her bedroom so as she was growing up, every time she went out she would go past it.

“She always said it gave her motivation, also the fact it was in the family made it seem normal and achievable.”

There was disappointment, though, for 2012 silver medallist Luke Patience and Chris Grube in the men’s 470, who dropped to fifth ahead of the medal race, which is where they finished after crossing the line in seventh.

In a remarkable finish to the skateboarding, Brown kick flipped her way into the history books and on to the podium with a score of 56.47 in her third and final attempt.

The teenager becomes Great Britain’s youngest Olympic medallist, an achievement all the more stunning considering the fractured skull and broken bones she suffered during a horrific fall in training last year.

Born in Miyazaki, Japan, to a Japanese mother and British father, Brown competed at the US Open in 2016 at the age of eight, and was first elected to compete for Great Britain in 2018.

She said: “I was a little nervous but I’m happy to be here and honestly, I just wanted to land my trick. I didn’t really care what place I got, I wanted to land my trick.

“I really hope I inspire some girls. I feel like people think I’m too young and I can’t do it but if you believe in yourself, you can do anything. I believed in myself and I’m here.”

Elsewhere, Team GB’s Ben Whittaker won Olympic silver in the men’s light-heavyweight boxing gold, while Frazer Clarke took bronze in the men’s super-heavyweight division.