Queen Christine: No doubt Ohuruogu is the golden girl of the one-lap event

Christine Ohuruogu is undisputed queen of the 400metres. There can be no doubt of that now she is the Olympic, World and Commonwealth champion.

Like it or not, the woman who forgot to be where she said she would be when the drug testers called was in all the right places at the right times in Beijing's Bird's Nest Stadium when she became the first British woman to win the Olympic gold medal for one lap.

Precious: Christine holds her Olympic gold after the medal ceremony in Beijing

The athlete from the London borough of Newham, where the Games will be staged in 2012, whom the British Olympic Association ruled should never represent the country at an Olympics before an independent appeal panel overruled them, won Britain a 16th gold medal and the athletics team their first.

Tears streamed down her face more than an hour after the finish as she said: 'You always have all these dreams about winning but you never think your dreams will be reality. I just ran across the line thinking 'I won'. I am so, so happy.'

Last August, when she won the world title 24 days after the end of a one-year suspension for missing three visits by the drug testers, there remained questions.

Not so much about her integrity because no less an authority than the Court of Arbitration for Sport proclaimed her innocence of anything more than forgetfulness.

The doubts were about whether she could legitimately claim to be the world's No 1.

Sanya Richards, ill when the United States selected their team, was not on the track in Osaka to dispute her supremacy but merely a spectator in the crowd.

Last night, Richards, the golden girl of U.S. track athletics, was there, apparently in her prime, and Ohuruogu beat her in an action replay of how she won last year.

Richards, a Jamaican-born Texan ranked world No 1 by the IAAF for the last two years, said: 'She beat me fair and square.'

In fact, Ohuruogu, 24, beat her even more decisively than those who were there in Richards' absence last year, pacing her race to perfection to take her home in one piece while others fell to pieces.

Richards ran the first 200m too fast and was treading water in the final 50m, her resources spent. Shericka Williams, of Jamaica, who took the silver, started too slowly and could not make up the ground.

Burn out: Sanya Richards let her lead slip and had to settle for bronze

Ohuruogu came off the final bend in fifth place, seven or eight strides down on Richards and behind Russians Tatiana Firova and Yulia Gushchina and Botswana' s Amantle Montsho, the fastest at the distance this year.

It was twice the margin of lead she allowed her rivals in Osaka but again she kept running as they died on their feet, none more completely than Richards, who was also overtaken by Williams.

Coincidentally, Ohuruogu's time of 49.62sec was just one-hundredth of a second slower than she managed last year.

'My coach (Lloyd Cowan) says that the race is always going to be won in the last 50 metres. It doesn't matter what you do before, it's won in that last 50 and you need to keep your cool and your composure for the last 50.

'That last 50 is when people start dying and everyone knows that I don't die. If you are going to beat me in championships you have to fight very, very hard.

'My coach always says you train for three days and three days only. You don't train for Grand Prixs, you don't train for the AAAs, you train for three days.

'If you're at your best for those three days then that's what it's all about. It's not about running the fastest time or whatever. It's about the gold medal.'

Richards blamed a 'hamstring grab' after 320m for slowing. 'I pulled my leg through and it got tighter and tighter,' she said but more likely what she was feeling was the effects of too much acceleration too soon.

'This is so devastating for me,' said the 2006 World Athlete of the Year.

At least she had the good grace to step back from the comment she made last week when she voiced the opinion that Ohuruogu was fortunate to be at the Games.

Last night she said: 'We are all lucky to be here. She is a great athlete.'

The smile on Ohuruogu's face after she crossed th line illuminated the stadium.

When they called her name at the medal ceremony, she almost jumped to the top step, her delight apparent.

Lord Coe kissed her on both cheeks when he presented her with flowers on the podium, and his next gesture as chairman of the London Organising Committee must surely be to restore the woman from Stratford to the role she once occupied as the face of 2012.

She said she had not slept for two days because the pressure was getting to her. 'As it gets closer it gets harder and you get scared,' she said.

'I'm just so grateful that I have been given an amazing talent.

'This isn't about revenge for the year out. I won the World Championships last year, so that's gone now. I'm not going to say anything about that. I've come here, got what I wanted, so I am happy.'

No doubt, she slept well last night.