South Africa's double Olympic 800m champion Caster Semenya finished just sixth in the 5,000m at the African championships on Thursday, missing the qualifying time for next month's world champs in Eugene.
In her first international race for South Africa since the 2018 Commonwealth Games where she won the 800 and 1500m, Semenya clocked 16min 03.24sec, well off the 15:10.00 mark required for selection for the Eugene worlds.
Semenya has just five weeks before the July 15-24 worlds in which to try to get the qualifying time. Her personal best is 15:31.50, set in April this year.
Kenya's Beatrice Chebet won the race in the Cote d'Or National Sports Complex in St Pierre, Mauritius, in 15:00.82 ahead of Belayneh Azale of Ethiopia.
Semenya, a three-time world champion over 800m, was forced to make the switch from her favoured distance to the longer event due to gender eligibility rules that required her to take testosterone-reducing drugs to compete in races between 400m to a mile.
World Athletics bar women athletes with high testosterone levels from competing in shorter races because the governing body says the hormone increases muscle mass and oxygen uptake.
Semenya, who became a world champion at 18 years of age in Berlin in 2009, has made several unsuccessful legal attempts to overturn the ruling.
In a bid to compete at the Tokyo Olympics, she even dropped down to the 200m, but was unsuccessful in her attempts to qualify.
Elsewhere on the Mauritius track, Ferdinand Omanyala was crowned the new African men's 100m champion, beating defending champion Akani Simbine of South Africa in a photo-finish.
Already the African record holder with a time of 9.85 seconds set in Nairobi in May, Omanyala clocked 9.93sec to land Kenya's first African 100m title in 32 years.
Simbine was three hundredths of a second behind Omanyala for the second time this year.
"The African record holder is now the African champion. Thanks to my team," Omanyala tweeted after the race.