Perri Shakes-Drayton has expressed her happiness at the way she performed during her 400m hurdles heat this evening.

The 23-year-old British athlete came out on top in the final race of her discipline, something that she has admitted was her ambition from the start.

"I thought I've got to treat this like a final. I tried to stay relaxed," she told BBC Sport.

"The main thing was to qualify for the next round. I did want to win so it's a good start."

The semi-finals take place tomorrow evening.