Britain's Daniel Fogg won his maiden World Cup race as he took gold in the Fina 10km Marathon World Cup in Mexico.
The 25-year-old beat Germany's Olympic silver medallist Thomas Lurz into second in the fourth leg of the series, with Italy's Simone Ruffini third.
Loughborough's Fogg, who finished fifth in the 10km at London 2012, won in one hour, 56 minutes 38.1 seconds.
Swansea swimmer Tom Allen and Sheffield's Tom Sunter finished 11th and 28th respectively.
Berni Dietzig, British Swimming interim head of open water, said: "The boys have done a great job to achieve this result and the race was very challenging.
"He was continuously challenged for the lead by some of the world's best open water swimmers over the last 2km, but he displayed his strength and determination and defended his position into the finish."
Lucinda Campbell, 16, of Windsor, finished 34th out of 50 in the women's event.