Allyson Felix clocked 49.67 seconds, the fastest time in Sunday’s 400m semifinals, to win heat three and advance to Monday’s final.
Felix, the 2015 400m world champion, is running the individual 400m for the first time at the Olympics. But she does have two Olympic 4x400m gold medals.
U.S. sprinter Phyllis Francis won the first heat in 50.31 seconds.
Jamaica’s Shericka Jackson and American Natasha Hastings both broke 50 seconds in heat two to advance to the final.
2008 Olympic 400m champion Christine Ohuruogu of Great Britain did not advance to the final after finishing fifth in her heat. 2012 Olympic 400m champion Sanya Richards-Ross is working as an analyst for NBC in Rio.
The women’s 400m final will take place Monday at 9:45 p.m. ET.