Sally Pearson was certain she had won the Olympic 100m hurdles gold medal as soon as she flashed across the finish line on Tuesday night. So was her coach Sharon Hannan.

But that certainty wavered somewhat in the minute - which felt more like an hour - before the photo finish confirmed she had edged defending champion Dawn Harper by two hundredths of a second.

Pearson's winning time of 12.35 seconds was an Olympic record and the second fastest of her career - behind only the 12.28 she ran to win the world title last year in Daegu.

And she needed to be at her very best on Tuesday as minor medallists Harper (12.37) and fellow American Kellie Wells (12.48) ran big personal bests to push her all the way in difficult wet conditions at the Olympic Stadium.

"I thought I'd won and looked to my left and went 'oh, maybe I didn't'," said the 25-year-old Pearson.

"It was quite close.

"When I saw my name on the screen at No.1, it was a dream come true.

"I've got every title now that I've wanted to win, now it's just have fun and relax.

"I knew I was in the lead but I didn't know where everyone else was.

"I had a bit of a panic, but I knew in my heart I'd won it and it was just a matter of confirming it on the screen.

"The feeling is just relief. I'm so happy."

Hannan was relieved too.

"I couldn't believe it was only two hundredths," she said.

"I thought she was two metres in front from the angle we were sitting at."

Hannan was surprised by the narrow margin of victory, while acknowledging that Harper - who had never run faster than 12.47 before doing so in the semi and again in the final on Tuesday night - was a "big-event performer".

The last five Olympic pre-race favourites in the 100m hurdles had all failed to win the ultimate prize.

A different type of hurdling curse struck again earlier on Tuesday when Chinese superstar Liu Xiang crashed out with a serious leg injury for the second straight Games without clearing a single barrier.

But none of that affected Pearson who hugged Hannan, husband Kieran Pearson and her mother Anne McLellan after the race before setting off on an emotional lap of honour.

It was Australia's 20th Olympic track and field gold medal and the first won by a woman in the pre-eminent sport of the Games since Cathy Freeman's unforgettable triumph on home soil in the 400m in 2000.

Pearson joins Freeman and pole vaulter Steve Hooker as the only Australian athletes to win gold at the Olympics and the world championships.

Harper (gold) and Lolo Jones (fourth on Tuesday) were the only other survivors from the 2008 final in Beijing when the then Sally McLellan announced herself to the world with a shock silver medal.

Last year she was the most dominant women's track and field star on the planet, a status acknowledged when she was voted the IAAF's world female athlete of the year.

Pearson has only been beaten twice in the last two years - at last year's Diamond League final in Brussels when she crashed into a hurdle and at last month's Diamond League meet in London, when she was pipped by Wells in atrocious conditions.

The women's sprint hurdles is Australia's most successful Olympic track and field event, with Shirley Strickland (1952 and 1956) and Maureen Caird (1968) having previously claimed gold when it was contested over 80m rather than 100m.

Pearson said the gold medal was reward for a lot of sacrifice by those close to her, including her mother.

"For so many years she sacrificed everything I guess. Her life," she said.

"I'm not the only one out there whose parents have sacrificed things.

"It's a really special moment for everyone who's competing at the Olympic Games who are realising their dreams here."

Pearson also thanked her high school sweetheart and now husband Kieran.

"He's been the biggest support, he cops a lot from me when I'm going through bad times and bad sessions or I'm frustrated by something."

NZ Newswire

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