200 meters at the Prefontaine Classic meet, finishing third with a season's best of 22.44 seconds. As the winner of the 2014 IAAF Diamond League 200-meter title, Felix received a bye into the 2015 World Championships in Athletics. Obligated to participate in the 2015 USA Outdoor Track and Field Championships but not required to run the 200 meters, she opted for the 400 meters. Felix won the event in 50.19 seconds with a late surge from fourth place at the 300-meter mark, catching Natasha Hastings right before the finish line to earn her ninth U.S. championship title. World number one ranked Francena McCorory and number two Sanya Richards-Ross failed to qualify for the 2015 Beijing World Championships. The 2015 Beijing World Championships schedule placed the 400-meter final just over an hour after the 200-meter semi-finals, making it virtually impossible to perform to world championship level in both events. As of July 1, Felix held the fastest seed time in both the 400 (0.11 over the fastest competitor) and 200 (0.22 over the fastest competitor), leaving her with a difficult choice as to which event to put her full effort into. Felix eventually chose the 400 meters and later triumphed in the event final with a personal best of 49.26 seconds. She dominated the race from beginning to end, making up the stagger from the start of the gun and never relinquishing her lead to claim the 400 meters title. In doing so, Felix became the first woman to win world titles in the 200 meters and the 400 meters. Additionally, she has now won the most world championship gold medals, and most overall world championship medals, out of any American track and field athlete. She continued to add to her medal collection by earning silver medals in both the 4 × 100 meters relay and 4 × 400 meters relay. In the latter race, Felix received the baton with a significant deficit to the leading Jamaican team, prompting her to sprint a historic split time of 47.72 seconds to regain the lead for the American women before the final handoff. This was the fastest 4 × 400 meters split ever recorded by an American woman and third-fastest 4 × 400 meters split ever by any female athlete, after Jarmila Kratochvílová and Marita Koch. Running the final leg, Francena McCorory failed to hold onto the lead and was overtaken by Novlene