Almaz Ayana of Ethiopia set a world record in the 10,000 meters with a stunning solo run to win the first gold medal of the athletics program. Vivian Cheruiyot of Kenya took silver.
Ayana finished in 29 minutes, 17.45 seconds. The old record of 29: 31.78 of China's Wang Junxia stood since 1993.
At 24, Ayana is now poised to become the next dominating long-distance runner and is also going for gold in the 5,000 meters next Friday. She is unbeaten this season.
Tirunesh Dibaba took bronze, missing out on the chance to become the first woman to win three individual gold medals in a row.