Cape Town - Sprinter Wayde van Niekerk and hurdles prospect Lindsay Hanekom were the star performers on Friday, setting world-class times on the opening day of the ASA Open Championships in Bloemfontein.
In the morning session, Van Niekerk crossed the line in 44.11 seconds, setting the second fastest time in the world this year in his 400m heat.
He later withdrew from the semi-finals as a precaution against a back injury due to the cool afternoon conditions.
"We wanted to see if we were on schedule, in preparation for the European season," said Van Niekerk's coach, Ans Botha.
"The conditions for the heats were nice and warm without wind, and I expected a low-44, so we're happy."
Hanekom was also in fine form, storming around the track in 49.03 to chop 0.43 off his 400m hurdles personal best as he achieved the qualifying standard of 49.40 for the Rio Olympics.
"I just came out today and did my best," Hanekom said. "My coach (Nico van Heerden) told me to go out hard because I don't know what the conditions will be like for tomorrow's final.
"That's what I did, and I got a good personal best, so I'm happy."
Among the other highlights, Henricho Bruintjies won the men's 100m final in 10.21, holding off a charge from Emile Erasmus, veteran hammer thrower Chris Harmse secured victory in the hammer throw (72.15m), nearly 10 metres clear of his nearest challenger, and Orazio Cremona earned the men's shot put title with a best heave of 19.38m.
Junior athlete Simonay Weitsz stunned her senior opponents to win the women's 1 500m race in 4:25.14, and versatile athlete Maryke Brits was triumphant in the women's long jump final with a best leap of 6.37m.