Williams, the former Kell High School star, ran the race in a meet-record 12.89 seconds. Fellow American Dior Hall was second at 12.92, breaking the U.S. high school record set in 1989.
Williams, who just wrapped up her freshman season at Georgia, was the U.S. junior champion in the 100 hurdles, as well as the NCAA heptathlon champion and the NCAA indoor pentathlon champion.
“I got out well and went through the hurdles well but I could see Dior peripherally and that helped push me,” Williams said. “This is my last junior meet and I wanted to go out with a bang. I think I did that.”
Kendall Baisden kicked the final 100 meters and the U.S. women in the 1,600 relay. Baidsen, who will be a sophomore at Texas, pushed the women across the finish in 3:30.42. Earlier in the week, she won the 400.
The U.S. men also won the 1,600 relay in 3:03.31 to cap the six-day international track and field event. On Saturday, the U.S. men and women also claimed golds in the 400 relays.
Alfred Kipketer of Kenya won the men’s 800 meters in 1:43.95. Countryman Barnabas Kipyego won the 3,000 steeplechase in a personal-best 8:25.59.
Morgan Lake of Britain won the women’s high jump at 6 feet, 4 inches. Lake also won the world title in the heptathlon earlier in the week, making her the first person to win both events at the worlds.
Dawit Seyaum of Ethiopia won the 1,500 in 4:09.86 on her 18th birthday.
Lazaro Martinez of Cuba won the men’s triple jump with a leap of 52-2½, while Gatis Cakss of Latvia won the javelin with a throw of 242-11.
It is the first time the junior world championships have been held in the United States. Nearly 1,600 athletes from 170 countries are took part in the six-day event, which included athletes born between 1995 and 1998.
There were reports Saturday that four Ethiopian athletes had left the meet and were unaccounted for. The Oregonian newspaper reported that University of Oregon police, along with the Eugene police and other law enforcement statewide were seeking to contact the athletes. It is not believed that the athletes are in danger.
It is not uncommon for athletes seeking asylum from unstable countries to use sporting events as a way to leave, although it is not known if the Ethiopians were seeking to flee their country.