American Haley Anderson claimed the first gold medal of the world swimming championships when she pipped Brazil's Poliana Okimoto to the line to win the women's open water 5km event on Saturday.
The 21-year-old Anderson thrashed around two laps of the harbour course at the end of the Rambla tourist drag in the heart of Barcelona in a time of 56 minutes and 34.2 seconds on a sweltering day in the Catalan capital.
Okimoto finished a mere 0.2 seconds back, with her compatriot Ana Cunha some 10 seconds behind in third.
Anderson's success, her first medal at a world championships, adds to the silver medal she won as a member of the U.S. Olympic 10km open water team in London last year.
The men's 5km event takes place later on Saturday (1100 GMT).