Jamaica’s Shericka Jackson claimed gold in the second-fastest time in history, winning in 21.45, only 0.11 seconds off the 34-year-old world record.
Jackson’s compatriot Shelly-Ann Fraser-Pryce, who won 100m gold earlier in the week, was second in 21.81 seconds.
Jackson, who failed to make the 200m semi-finals at the Tokyo Olympics after easing up too early in her heat, has been in spectacular form this season.
The 28-year-old is the fastest in the world this year and qualified fastest for the final.
Defending champion Dina Asher-Smith brought another medal back to Britain — the only of the six women’s sprint medals not heading back to Jamaica this year.