Russia's Mariya Savinova has won gold for Russia in the women's 800m final with a time of 1:56.19.
The favourite Caster Semenya timed her sprint finish too late, and despite making up three places on the home straight, could only take silver with 1:57.23.
Russia also claimed bronze, with Ekaterina Poistogova being pipped on the line by Semenya but still managed a personal best of 1:57.53.
Defending champion Pamela Jelimo of Kenya could only manage fourth in what was a disappointing finish.