In her darkest hours the loneliness of the 400 metres runner was almost too much to bear. Christine Ohuruogu thought about quitting. She thought about fleeing the country. In the end, with the naysayers demanding retribution and a jaundiced dream of competing at the London Olympics a mile from the family terrace, she refused to run away. Instead she ran her way.

When she reached the semi-finals at the Athens Olympics and then won gold at last year’s Commonwealth Games she was filed under “future”. But then she missed a third drugs test and her future was a muddied mess. That Linford Christie, who received a two-year ban for doping, said she was “naive not guilty” was a flawed defence for the suspicious.

Some will think she got what she deserved, but one of her teammates here, Tasha Danvers-Smith, leapt to her defence and explained how easy it is to fall foul of the testers. She revealed that she, too, had missed a drugs test in April, but had managed to convince the doping chiefs that it was an honest mistake. “They said I was not at home and I knew for a fact that I was,” she said. Danvers-Smith, who lives in the United States, even enlisted the Los Angeles Police Department to try to check her phone records. “A lot of people who vote on the system do not understand,” she said. “One [missed] test can screw up your whole career.”

Ohuruogu, 23, fell foul of the three strikes in five years rule when she went to train at Crystal Palace one day. She consulted her family –– she has five brothers and a sister –– and took her case to the Court of Arbitration for Sport (CAS) in Lausanne in April. It proved in vain. Even though CAS accepted that hers was a case of a “busy young athlete being forgetful”, it upheld the verdict. She spoke of retiring and of using her parentage to run for Nigeria. She was, as Lloyd Cowan, her coach, admitted, desperate: “She was very emotional and very low.”

Cowan kept her training, a parlous task given that there was no prospect of being able to compete. Indeed, with her legal fees mounting, it all seemed too much effort. Another life was a tempting siren. “I’m glad I didn’t quit,” she said after becoming the first British woman to win a gold medal at 400 metres at either a World Championships or Olympics. “There was despair, but I don’t think I’d have forgiven myself if I hadn’t stuck through. When you feel bad you feel you can’t be a***d, but I’m proud I kept my head down, worked and set my goals. I told myself you’ve got a talent.”

There were more problems for the former UCL linguistics student who once played netball for England. Two operations left her in plaster at the end of last year and she began jogging again only in January. Physically and mentally, she was at her lowest ebb.

Her suspension ended on August 5, although she is still banned by the British Olympic Association. The bold decision to pick her for Osaka invited scorn when she made her comeback away from the media spotlight in Glasgow and ran a tardy 53 seconds.

However, her efforts in a pre-championship meeting in an empty Nagai Stadium last Thursday made people sit up. She ran 50.46 in her heat and 50.17 in the semi-final, although Nicola Sanders, who trains at Eton, looked the better bet for gold after becoming the fourth Briton to run a sub50 lap.

And so they came to the final. With Sanya Richards, the world’s fastest 400 metres runner, missing after failing to qualify from the United States’ sudden-death trials and Ana Guevara, of Mexico, drawn in the outside lane, hopes were high. However, initially, the British looked out of it as Novlene Williams, of Jamaica, and Natalya Antyukh, of Russia, entered the home straight in the gold and silver spots, but Ohuruogu’s mixed emotions dredged her spirit and snaffled victory from Sanders, with Williams third.

The men’s 1,500 metres followed, which, by a quirk of fate, might also have been termed a redemption song. Bernard Lagat was caught up in a drug scandal at the 2003 World Championships, only for his innocence to be proved later. “It was the worst time in my life,” the American said after winning gold, “but having a day like this lights up everything. It lights the past, the moment and the future.”

Ohuruogu will hope he is right.