Olympics-South Africa's Semenya takes 800 metres gold

Burundi's Francine Niyonsaba finished in 1:56.49 seconds to claim the silver, her country's second medal in any sport at the Olympics. Kenya's Margaret Wambui took bronze in 1:56.89.

Semenya has dominated the 800m this season and there had been speculation she could take down Czech Jarmila Kratochvilova's 1983 time of 1:53.28 seconds - the longest standing athletics world record, set in an era when eastern European doping was rife.

After winning the silver medal in London four years ago, the 25-year-old South African has recorded three of the four fastest times in the world this year.