Jamaica's Veronica Campbell Brown has won the first women's 200m semi-final in a season's best time of 22.32s ahead of Carmelita Jeter of the United States.
The 100m bronze medallist was drawn in the outside lane but ran a strong bend before fighting off a late charge from Jeter, the 100m silver medallist.
Great Britain's Margaret Adeoye finished seventh and failed to reach the final.