Denmark's Pernille Blume beat the favorites to win the 50 meters freestyle in 24.07 seconds on Saturday and give her country a first Olympic swimming gold medal since 1948.
Simone Manuel of the United States, the 100m freestyle gold medalist, took the silver in 24.09 and Aliaksandra Herasimenia of Belarus the bronze.
Ranomi Kromowidjojo, the 2012 Olympic champion, finished sixth while Australia's Campbell sisters Cate and Bronte again failed to medal in an individual sprint.
The gold was Denmark's third in swimming, and Blume's first of any color at an Olympics. The other two were won by Karen-Margrete Harup (100m backstroke) and Greta Anderson (100m freestyle) at the 1948 London Games.