In 2003, she defended her title in the 400 m at the 2003 Pan American Games winning the gold medal. She won the 400 meter race at the Weltklasse Zürich, one of the two 400 m events held at Golden League competitions that year. Later, on August 27, 2003, in Paris, France, she won the 2003 World Championships in Athletics in the women's 400 meters. She set a personal record, a national record, and a world leading time, finishing in 48.89 seconds. She won the 400 m at the 2003 IAAF World Athletics Final in Monaco.