Usain Bolt remained unbeaten in two races this season, winning the 100 meters in 9.91 seconds Tuesday at the Golden Spike meet but unhappy with his time.
He pulled away from fellow Jamaican Steve Mullings to match his time in Rome last week. Mullings finished in 9.97 for second place, and Daniel Bailey of Antigua was third in 10.08.
The race was held with a slight headwind, but Bolt said he had expected to improve on his performance in Rome, where he edged Jamaican rival Asafa Powell.
"My time, 9.91, is not bad, but it could be better," Bolt said. "I expected faster time."
Bolt has broken the 100 record three times, the last time in 9.58 at the 2009 worlds in Berlin. He also holds the 200 world record.
He cut short last season because of back and Achilles' tendon problems and is still trying to find his form this year.
"I'm just coming back from injury," he said. "It was just my second race in nine, 10 months. I just never come out and run 9.8 or 9.7. It's not going to happen. I'm taking a step at a time, a race at a time."
Bolt's next stop will be the Bislett Games, a Diamond League meet in Oslo on June 9, as he warms up for the Aug. 27-Sept. 4 world championships in Daegu, South Korea.
"If I lose here, if I lose next week or tomorrow, anytime, it's never about that. It's all about the world championship," Bolt said. "I have a lot to do. My main focus is to get back into good shape, I don't really worry about world records."
Double-amputee sprinter Oscar Pistorius was no closer to qualifying for this year's world championships and next year's Olympics after finishing in 46.19 seconds to place sixth in the 400 meters. The South African, known as the "Blade Runner," needs to run a personal-best 45.25 seconds to qualify for the worlds.
"I thought I could have done better," Pistorius said.
He ran a personal best of 45.61 in Pretoria in March and will have more chances at American meets in Portland, Ore., and New York City.
Veronica Campbell-Brown was more impressive, turning in a personal best and world-leading time of 10.76 in the women's 100. Campbell-Brown is a double Olympic champion in the 200, but looks likely to be a contender in the shorter sprint as well at the worlds.
"PB didn't surprise me because I feel I can improve it," the Jamaican said.
Francena McCorory of the U.S. took the women's 400 in 50.64, followed by Denisa Rosolova of the Czech Republic and another American, Sanya Richards-Ross.
L.J. Van Zyl of South Africa maintained his perfect start to the season, winning the men's 400 hurdles in 47.66, equaling the world-leading time he ran in Pretoria in February.
Marvin Anderson led a Jamaican sweep in the men's 200, running a 20.27 to beat Yohan Blake and Mario Forsyth. Olympic champion and world-record holder Dayron Robles of Cuba ran 13.14 to win the men's 110 hurdles.