South Africa’s Caster Semenya won Olympic gold in the 800m but Great Britain’s Lynsey Sharp missed out on a medal as she finished sixth.
Semenya, 25, set a national record to win in one minute 55.28 seconds and finish well clear of silver medallist Francine Niyonsaba of Burundi.
Kenya’s Margaret Nyairera Wambui took the bronze medal, while Scot Sharp set a new personal best of 1:57:69.
Semenya, who has been subject to gender testing, won silver in 2012.
She finished behind Mariya Savinova in London, but since then the Russian has been named in a doping report and could receive a lifetime ban.