World champion Lashinda Demus progressed through to the semi-finals of the women's 400m hurdles this evening.
The 29-year-old from the United States ran a positive opening 300m, which gave a healthy lead over her rivals.
As a result, she eased down in the closing stages, clocking a time of 54.60 seconds as she crossed the line.
The three remaining qualifying places went to Hanna Titimets, Vera Barbosa and Elena Churakova.