Keri-Anne Payne has missed out on a medal in the women's 10km marathon.
The Team GB swimmer was among the favourites to make the podium at the Serpentine this afternoon, but could only manage fourth place behind strong opposition.
Payne maintained a place in the top three throughout the early laps, but struggled to keep up with the pace set by gold medal winner Eva Risztov of Hungary.
Risztov broke into a significant lead in the sixth lap, and narrowly held it come the end of the race, edging out silver medallist Haley Anderson of the United States.
Martina Grimaldi of Italy secured bronze, digging deep in the final straight to reach the end one second ahead of Payne with a finish time of 1:57:41.8.
The endurance-testing race claimed two casualties; Jessica Roux of South Africa struggled to keep up from the off and bowed out on lap three, while Brazil's Poliana Okimoto was rescued into lap four.
