Rose, from Cleveland, Ohio, was an easy victor in the women's five-kilometre open water event on a benign Indian Ocean course. Her victory also led the United States to a team gold medal, added to the results of John Flanagan and Austin Ramirez in the men's event, over the same course, earlier. Flanagan was eighth and Ramirez 15th behind Russia's Alexei Akatiev, who took the first gold medal of the event.
Rose left the pack behind at the half-way mark of her first major international meet and was never troubled. She finished in 59min, 23.5sec. Edith van Dijk, of the Netherlands, was second in 1:58.80 with Peggy Buchse, of Germany, third in 1:01.05.80.
"It was a surprise that I was as far ahead as I was, but I'm not surprised I won it," Rose said. Despite her confidence, Rose's previous best performance was a third place at last year's Pan Pacs in the 1500m event behind two compatriots.
Great Britain's Paula Wood finished in 17th place.
Akatiev, Russia's double European champion, made the most of calm conditions to take gold in the men's event. Akatiev, a 1500m finalist in the pool at the Atlanta Olympics, overtook the Australian teenager Ky Hurst about 400 metres from the finish to finish in 55min 18.60sec.Reuse content