American Tyson Gay and Asafa Powell of Jamaica are set to square off against each other again in the 100 metres at the DN Galan athletics meet today.

In their last head-to-head meeting in Rome this month, Gay posted the fastest time of the year in 9.77 seconds. Powell was second in 9.88.

Three other American sprinters - Travis Padgett, Darvis Patton and Rae Edwards - have entered today's race.

Gay won gold medals in the 100, 200 and the 4x100-metre relay with the American team at the 2007 worlds, but he did not compete in Stockholm last year after a series of injuries. Gay won the 200-metre race at the London Grand Prix in 20.00 seconds this past weekend, but then needed painkillers to numb an aching groin.

"This is my last race before the world championships, so it's very important," said Gay, who is seen as one of the leading challengers to world record-holder Usain Bolt in Berlin next month.

"The (Olympic Stadium) track is fast, but the fans and conditions are the reasons for world records," added Gay. "I'm sure everyone is lining up to run their personal best, as myself."

Powell is attempting to become only the second man in history to post more than 50 sub-10 second results in the 100. Maurice Greene of the United States tops the all-time list with 53.

A former world record-holder, Powell won last year's race in Stockholm in 9.88, edging eventual Olympic champion and fellow Jamaican Bolt by a hundredth of a second.

That was Powell's third straight win at the Olympic Stadium. In 2007, he won in 10.04. A year earlier, he set the stadium record of 9.86.

1-carat diamond

Every athlete who sets a new stadium record will earn a 1-carat diamond worth US$10,000 (€6,300).

Steven Hooker of Australia, who won the pole vault gold in last year's Beijing Olympics, also wants a diamond.

"I believe if the conditions are good (Russian) Rodion Gataullin's 20-year-old stadium record (5.95) is achievable," Hooker said.

Among other Olympic champions competing are Jeremy Wariner of the United States, Yurij Borzakowski and Tatyana Lebedeva of Russia, Dayron Robles of Cuba and Andreas Thorkildsen of Norway.

Wariner is looking for his fourth-straight win in the 400. His stadium record of 43.50 earned him a diamond in 2007.

A number of other Jamaicans will compete at the meet. In the 200 metres, world leader Debbie Ferguson-McKenzie will face Jamaica's Kerron Stewart and Allyson Felix, the 2007 world champion.

Jamaica's Ricardo Chambers and Michael Blackwood test their mettle against Wariner while in the women's one-lap event Shereefa Lloyd, Rosemarie Whyte, Novelene Williams-Mills and Clora Williams are all down to compete.

Selected races

(Ja times)

12:15 p.m.: Men's 400m

12:30 p.m.: Women's 100mh

1:20 p.m.: Women's 200m

1:30 p.m.: Men's 800m

1:40 p.m.: Women's 1500m

2:05 p.m.: Men's 100m

2:20 p.m.: Women's 400m