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Video - Tafton claims landmark gold
Stephanie Brown Trafton became the first American woman in 76 years to win the Olympic discus title.
Trafton's first throw of 64.74m was enough for victory, with Cuba's Yarelys Barrios taking silver with a second-round effort of 63.64m.
Ukraine's Olena Antonova collected bronze with a season's best 62.59m.
Brown Trafton's win was the first in the womem's event for the United States since Lillian Copeland claimed gold at the 1932 Los Angeles Games.
Mac Wilkins, who triumphed in 1976, was the last American winner of the men's discus.