Phenyo Bongani Majama (2nd, R) of Botswana celebrates after the men's 4x400m relay final at the 2021 World Athletics U20 Championships in Nairobi, Kenya, Aug. 22, 2021. (Xinhua/Zhang Yu)

Members of team Nigeria pose for pictures after the women's 4x400m relay final at the 2021 World Athletics U20 Championships in Nairobi, Kenya, Aug. 22, 2021. (Xinhua/Li Yan)

Team Nigeria (R) compete during the women's 4x400m relay final at the 2021 World Athletics U20 Championships in Nairobi, Kenya, Aug. 22, 2021. (Xinhua/Zhang Yu)

Athletes of Botswana (R) compete during the men's 4x400m relay final at the 2021 World Athletics U20 Championships in Nairobi, Kenya, Aug. 22, 2021. (Xinhua/Zhang Yu)

Members of team Nigeria (C), team Jamaica (R) and team Italy pose after the women's 4x400m relay final at the 2021 World Athletics U20 Championships in Nairobi, Kenya, Aug. 22, 2021. (Xinhua/Dong Jianghui)