Russian world champion Mariya Savinova built a large enough cushion to hold off a charging Caster Semenya of South Africa to win the 800 metres Olympic title on Saturday.

Savinova timed 1min 56.19sec to Semenya's 1:57.23 while another Russian, Ekaterina Poistogova, took bronze

Semenya was last heading into the back stretch and may second guess her tactics for the race.

"We all make mistakes, hopefully the next race will be better," said Semenya.

"It was a good race, I am happy with the result. I left it a bit late, but I am happy with the silver. But my coach is not really happy but Savinova is a good athlete, a good competitor.

"I just need to train harder. I must let the (Russians) know I'm there."

"I've been waiting all year for this," said the 21-year-old.

"The last four years have not been easy. I'm already thinking about Rio (2016 Olympic Games) and I hope I'll be there."

Kenya's defending champion Pamela Jelimo took the lead 300 meters from the finish but faded finishing fourth.

"I knew the Russians were very strong," said Jelimo.

"What can you do? You have to accept that sometimes you are at the top and sometimes you are not."

"My body did not stick to the task, but for me it's the best I can do."