PRAGUE, Czech Republic (AFP) — A false start called late marred Asafa Powell’s best run of the season at the Czech Golden Spike event yesterday, which also saw Australia’s Olympic champion Sally Pearson back on the track after nearly a year.

Ethiopia’s 10,000-metre runner Tirunesh Dibaba and New Zealand shot-putter Valerie Adams both produced world-best performances in the eastern Czech city of Ostrava.

Jamaica’s Powell, the Olympic relay champion from 2008, crossed the line in the 100-metre race in 9.97sec, improving his season’s best of 10.02sec, but referees called the runners back over a false start when the pack was more than halfway through the race.

Half an hour later, the 30-year-old Powell covered the distance in 10.06sec, ahead of Kim Collins of St Kitts and Nevis and US sprinter Mike Rodgers.

“I was a little disappointed the first run did not make out. I’m happy to win, but not satisfied with the time,” Powell said.

Powell was originally scheduled to run a relay against the Racers Track Club’s team featuring Usain Bolt and Yohan Blake, but the Jamaican stars pulled out, forcing the organisers to insert a 100-metre race instead.

Reigning 100m hurdles Olympic champion Sally Pearson returned to the track after being sidelined for almost a year, winning her race in 12.67sec.

“The time is a good sign for the World Championships in Moscow, but I definitely wanted to run faster,” said the Australian.

“I haven’t competed for 11 months, therefore I’m satisfied with the result,” she added.

Ethiopia’s reigning Olympic champion Tirunesh Dibaba set the year’s best time in the 10,000 metres, clocking 30min 26.67sec but complained about the cold breeze on an otherwise sunny day.

“I’d say I could run much faster, but it was a little bit windy and the pacemaker did not run the way I wanted,” she said.

Compatriot Kenenisa Bekele, triple Olympic champion, yet uncertain of a spot at the world championships in Moscow in August, could only finish fourth in the 5,000 metres, overshadowed by another Ethiopian runner, 19-year-old Edris Muktar.

New Zealand’s Valerie Adams, also a champion from London, scored this year’s best in shot put with 20.88 metres.

“I improved attempt by attempt and hopefully the 21-metre mark will be reached soon. This is a good sign for the world championships,” said Adams.

Grenada’s Kirani James, another London winner, took the 400-metre race in 44.49sec.

Kenya’s 18-year-old prodigy Conseslus Kipruto won the 3,000-metre steeplechase, while compatriot Milcah Chemos dominated the women’s race.