Former world champion Caster Semenya won her first 800-meter race of 2012 but was well outside the Olympic qualifying time in a sluggish season-opening run.
Semenya recorded 2 minutes, 3.60 seconds at a meet in northern South Africa on Saturday, nearly 4 seconds off the Olympic standard of 1:59.90. It was the 2009 world champion and 2011 world silver medallist's first competitive two-lap race under new coach and former Olympic champion Maria Mutola.
Semenya said she made an early tactical error but still called her season debut "a good race."
"I enjoyed it," Semenya told the South African Press Association. "I ran a little stupidly because I didn't take the lead from the beginning. I thought the other athletes would push the pace but we all learn from our mistakes.
"Everyone knows the Olympics is the most important thing this year, but first I must set the qualifying time and we'll take it from there."
The 21-year-old runner is hoping to qualify for her first Olympics later this year after a tumultuous three years that included missing 11 months because of gender tests, a lower back problem and new coach.
South Africa's Olympic hopefuls including Semenya have until June 30 to meet qualifying criteria for the London Games.
Mbulaeni Mulaudzi, another former world champion, won the men's 800 in 1:46.41, just under a second outside the Olympic qualifying time. It was Mulaudzi's return from a lengthy injury layoff.
L.J. van Zyl, who won bronze at last year's worlds in the men's 400 hurdles, struggled to fourth in the 400 flat at Potchefstroom.
The trio are expected to compete next at the South African Championships in the south coast city of Port Elizabeth next month. Athletics South Africa requires its Olympic competitors to appear at nationals.