Great Britain's Tiffany Porter has failed to reach to the final of the women's 100m hurdles after missing out on a fastest-loser position.
The 24-year-old was hoping that the third-placed runner in the final semi-final would not go faster than 12.79s, only for Phylicia George of Canada to run a personal best of 12.65s.
Kellie Wells won the final semi with a season's best time of 12.51s but she was outshone by Australia's Sally Pearson, who ran the fastest time in the world this year with a 12.39s.
America's Dawn Harper won the first semi-final with a personal best time of 12.46s.
The eight who qualified for tonight's final at 9pm:
1. Sally Pearson (AUS) 12.39s
2. Dawn Harper (USA) 12.46s
3. Kellie Wells (USA) 12.51s
4. Nevin Yanit (TUR) 12.58s
5. Phylicia George (CAN) 12.65s
6. Jessica Zelinka (CAN) 12.66s
7. Lolo Jones (USA) 12.71s
8. Beate Schrott (AUT) 12.83s