Derval O'Rourke has failed to qualify for the final of the women’s 100m hurdles at the London Olympics, finishing fifth in her semi-final.

O'Rourke will be disappointed with her run, as she only managed to equal her time of 12.91 in the first heat, and finished 15th fastest from the three semi-final races.

The top two from each semi-final qualified, along with the two fastest losers.

The Cork runner got off to a great start and was one of the front runners over the first fifty metres, however she was unable to maintain the pace and was caught in the second half of the race.

Australia's Sally Pearson, one of the favourites for the gold medal, won the heat in the season’s best time of 12.39.

Canadian Jessica Zelinka finished in second in a time of 12.66 to book her place in the final.