Australia's Olympic champion Sally Pearson has suffered an early season setback after breaking her arm in a crash in the 100-metres hurdles at the Rome leg of the Diamond League.

Loading...

Pearson, who won gold at the London Olympics in 2012, had gone halfway through the race before clipping the fifth hurdle and crashing to the ground where she was left clutching her hand and wrist.

A statement by Athletics Australia later said Pearson had "suffered a dislocation and a complex fracture of both the ulna and the radius in her left arm" and will "undergo surgery" immediately.

"She is in the hands of a very competent orthopaedic surgeon in Rome and is understandably devastated by the injury and in a great deal of pain," the statement read.

"It is however too early to tell what impact the injury will have on the remainder of her season and her hopes of competing for Australia at the 2015 IAAF World Championships in Beijing in August.

"It is anticipated that Pearson will return home to Australia once she has recovered from the surgery."

Sharika Nelvis of the United States took the win in a personal best of 12.52 seconds to go top of the Diamond Race with compatriot Dawn Harper-Nelson, a silver medallist at the London Games, second in a season's best of 12.59 seconds.

Loading

Britain's Tiffany Porter held on for third place under pressure from Belarusian Alina Talay.

American world champion Brianna Rollins, who won in Rome last year to end Harper-Nelson's four-year domination at the meet, failed to finish having also crashed out.

Compatriot Jasmin Stowers, who set a world leading time of 12.35 seconds in Doha last month, finished in 25.21 seconds after landing awkwardly and stumbling on the third-last hurdle.

Elsewhere, Australia's Dani Samuels picked up an impressive second place in the discus.

Samuels' first throw of 65.47 metres was her best, but Croatian Sandra Perkovic was unstoppable as she romped to victory with a best of 67.92 metres.

Perkovic's first (66.21) and fifth efforts (65.68) both would have been good enough for victory.

Cuba's Yaimi Perez finished third with a 65.30-metre throw.

Gatlin 'has nothing to prove' after breaking Bolt's Rome record

American Justin Gatlin snatched the track record held by rival Usain Bolt as he cruised to victory in the men's 100 metres in Rome.

Gatlin, the 2004 Olympic champion who served a four-year doping ban from 2006 to 2010 for using testosterone, stopped the clock at 9.75 seconds, the 11th-fastest time in history.

It was just one hundredth faster than the time of 9.76 set by Bolt, in Gatlin's absence, on his way to victory in the Italian capital in 2012.

Bolt, the Olympic champion and world record holder in 9.58, has made only one appearance in Europe this season, winning the 200 metres in the Czech Republic last month.

But with both sprinters avoiding each other so far in the build-up to the world athletics championships in Beijing in August, it is only a matter of time before they duel.

Gatlin said he would relish the competition if he were in Bolt's shoes.

"If the roles were switched ... I'd be more enthused by such a great competitor coming up and making me want to be sharper again," he said.

It is the second time Gatlin has run under 9.80 in just over a week, after storming his way to a personal best of 9.74 in Doha last week.

That performance raised eyebrows among his detractors, but Gatlin says he has nothing to prove.

"I have nothing to prove to anybody, really," he said.

"I just come out and just want to run. Good or bad, whatever is written about me, positive or negative, I wake up, get to the track and get ready to run."

France's Jimmy Vicaut was second in a season's best of 9.98, a time matched by American Michael Rodgers who tied for second place.

AFP/ABC