Christine Mboma added the 200m U20 world title to her Olympic silver medal in Nairobi on Saturday (21 August).
The 18-year-old clocked 21.84, just three-hundredths outside her world U20 record set in Tokyo, to lead home Namibian team-mate Beatrice Masilingi who was sixth in the Olympic final.
Masilingi, also 18, ran a personal best of 22.18 to take second from Nigeria's Favour Ofili (22.23) and add to her 100m silver on Thursday behind Jamaica's Tina Clayton.
In Tokyo, Mboma became the first Namibian woman to win an Olympic medal as she set a new African record of 21.81 behind Elaine Thompson-Herah just over two weeks ago.
Both she and Masilingi were barred from the 400m by World Athletics - the distance in which Mboma set U20 world and African records earlier this year - after returning tests which indicated differences in sexual development (DSD) and high natural levels of testosterone.