Kenya's Margaret Nyairera bags Bronze in women's 800m as South Africa's Caster Semenya wins Gold

Caster Semenya of South Africa took the gold medal in the Olympic 800 metres on Saturday in a personal best time of 1:55.28 seconds.

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.