Katarina Johnson-Thompson used to stare at the three-inch scar snaking down her left achilles tendon and fear that her best days had abandoned her. In truth, we all did. Yet here she was on the banks of the Danube, amid the tears and the doubts and the smiles, waltzing in the joy of becoming world heptathlon champion again.

“This is the best day of my life,” she said, after one of the great comebacks. “I had committed to getting my heart broken again, only this time I didn’t.”

Related: USA’s Noah Lyles wins 100m world title as Hughes seals bronze for GB

On a night when Zharnel Hughes also won Britain’s first men’s world 100m medal for 20 years, Johnson‑Thompson’s epic clash with the 22-year-old American superstar Anna Hall came down to 800m and a blunt equation. Stay within three seconds of Hall and the gold medal was hers. The problem was, her personal best was five seconds slower than her rival.

By now Hall had an enormous bandage protecting an injured left knee but she still blasted her way through halfway in 58 seconds – a second ahead of Johnson-Thompson. Yet by 600m the gap was stretching into the danger zone, and the British team feared gold was slipping away.

But when the second wind came – and the benefits of brutal sessions every week with her coach, Aston Moore, in Loughborough reaped their rewards – she began to close again.

“I can’t remember the race, I was just staring at her back,” Johnson‑Thompson said after crossing the line in 2:05.63, just 1.54sec behind Hall. “I was in full robot mode. I wasn’t thinking. I looked at the time at halfway and I thought ‘this is fast’. Normally I’d think ‘this is fast, you’re going to die, slow down’. But I just went with it. My instructions were not to let 20 metres pass.”

Johnson-Thompson knew victory was hers, even before the stadium scoreboard showed her final tally of 6,740 points, 20 ahead of Hall, with Anouk Vetter of the Netherlands third with 6,501 points.

Then came a moment both intimate and cosmic, as she reached over to hug Hall, who had fallen to the floor in exhaustion.“You fought like hell over these last two days, I respect so much how you kept going despite being banged up,” Johnson‑Thompson told her rival. Hall’s response? “It is super inspiring what you have done.”

A few minutes later, when she faced the world’s media, the 30‑year‑old Johnson-Thompson was asked whether she believed she could be a world champion again. “No. I didn’t,” she replied, fighting back more tears. “I just thought I’d fade into the background and be one of those athletes who is just there to make up the numbers.”

But who could blame her given that in 2020 she feared her career was over after tearing her achilles? Then at the Tokyo Olympics she had to leave the track in a wheelchair after tearing her right calf muscle. Truly Johnson‑Thompson could teach Judy Blume a thing or two about heartbreak.

This time, though, she was determined to write a different story. Johnson-Thompson had begun day two in second place, 93 points behind Hall, but immediately laid down a marker with a 6.54m long jump that catapulted her 19 points ahead.

Johnson-Thompson knew she needed more and further applied the squeeze in the javelin with a throw of 46.14m – the best of her career. No wonder she put her hands across her face in a mixture of joy and disbelief. Yet even greater elation was to come.

Shortly afterwards the British team were celebrating another medal as Hughes took a bronze in the 100m. Victory went to the brash American Noah Lyles, who came through in 9.83sec, while the 20-year-old Letsile Tebogo of Botswana took silver in 9.88, the same time as Hughes.

“It’s been years of trying, years of lessons,” Hughes said afterwards, as the tears flowed. “I wouldn’t call it failure – just years of lessons. Doubts were there. People probably didn’t believe in me, but I needed to believe in myself. The speed has always been there but the mind wasn’t aligned properly.”

The 27-year-old Briton had arrived in Budapest having shattered the British 100m and 200m records and set the fastest time in the world this year. But as he lined up for the final he knew this was not only about numbers but nerve.

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The last time he was in such company, in the Tokyo Olympic final, Hughes had false‑started. This time there was no mistake – but a slow pick‑up meant he had too much to do to win gold in the last 70m.

Not that Hughes was too disappointed with bronze. “Honestly it’s a dream come true,” he said. “In the past my thoughts were running wild. I was overthinking. This time I just let myself be free.”

There was also a helping hand from a former British Olympic and world champion, Linford Christie. “A big shout out to him,” Hughes said. “Linford said: ‘Just relax Zharnel. If you stay within the mix, you’re going to get a medal.’ I just listened. It was achieved.”