Hungarian swimmer Eva Risztov had the stamina to beat the field in the women's 10-kilometre open water swimming on Thursday after a close finish in Hyde Park in London at the Olympics.
Risztov won by just 0.4 seconds from Haley Anderson of the US, with Italy's Martina Grimaldi three seconds further back in third place.
Britain's Keri-Anne Payne, who won silver in Beijing four years ago, just missed on the medals in fourth place, 0.4 seconds behind Grimaldi.
The field was weakened by defending Olympic champion and eight-time World Champion Larisa Ilchenko's withdrawal due to health problems.
The men's 10km race takes place on Friday, and is the last swimming event of the Olympics.