"I came to the Bird's Nest to lay a golden egg, and that's what I did," Brown Trafton said. "I am surprised we haven't won more gold. But you know what? I hope this sets a trend."
The 28-year-old Brown Trafton, from Galt, Calif., won the Olympic title Monday with a best mark of 64.74 meters (212 feet, 5 inches).
Brown Trafton was third at the U.S. trials, but had the best throw by an American this season.
Yarelys Barrios of Cuba, a bronze medalist at the last world championships, took silver at 63.64 meters (208 feet, 9 inches) and Ukraine's Olena Antonova won bronze at 62.59 meters (205 feet, 4 inches).
Brown Trafton's gold medal was the first for the Americans in 76 years.