Derval O'Rourke in action in the 100m hurdles heats in Berlin
Derval O'Rourke produced a superb run to qualify for the 100m hurdles semi-finals at the World Championships.
O'Rourke clocked a season's best of 12.86 seconds as she finished .04 behind Australia's Sally McLellan.
Defending champion Michelle Perry was badly affected by a knee injury and failed to qualify by clocking 13.68.
Paul Hession squeezed into Wednesday's 200m semi-finals after coming through two rounds on Tuesday while David Gillick progressed in the 400m heats.
After clocking 20.66 to finish second in his morning qualifier, Hession improved to 20.48 in the second to take third behind Jamaica's Steve Mullings for the second time on Tuesday.
As was the case in his morning heat, Hession had to work hard to claim the final automatic qualifying place behind Mullings (20.23) and Azerbaijan youngster Ramil Guliyev (20.40).
On the basis of his two performances on Tuesday, Hession will struggle to get beyond the semi-finals.
Hession had work to do after his mediocre bend in his morning heat but he produced a fast finish to clinch one of the automatic qualifying spots ahead of Japan's Kenji Fujimitsu (20.69) and France's David Alerte (20.72).
Usain Bolt clocked 20.42 to win his second-round heat after jogging for the second half of the race and looks in a class of his own in the field.
Gillick finished behind Britain's Robert Tobin in his 400m heat
O'Rourke was 10th fastest of the qualifiers for Wednesday's semi-finals but a repeat of her personal best (12.72) from 2006 would probably be enough to make the final.
Her opening heat looked tough but Perry's injury opened the door for the Irish woman.
O'Rourke grabbed her chance by producing a splendid run, which left her just behind Olympic silver medallist McLellan and ahead of Russian Yuliya Kondakova (12.88).
Gillick had to work hard to finish second in his 400m heat in 45.54 which left him behind Britain's Robert Tobin.
Irish 1500m hopeful Deirdre Byrne and Deirdre Ryan both exited on Tuesday.
Byrne finished 11th in her heat in 4:12.19 who was over two seconds outside the time required for a fastest loser's spot and some way off her personal best (4:08.89).
Ryan cleared 1.85m at the third attempt but she failed to get over 1.89m and the eventual qualifying mark was 1.92, which is her Irish outdoor record set in 2006.
The Irish number one also cleared 1.93m indoors earlier this year.
Gillick, regarded as a genuine contender to make the 400m final after a 44.77 clocking earlier this summer, needed to produce a strong closing 100 metres to ensure his passage into Wednesday's semi-finals.
Tobin won the qualifier in 45.50 with Gillick (45.54) coming in ahead of Sudan's Rabah Yousif (45.55) and American Lionel Larry (45.64), who earned a fastest loser's spot.
In Gillick's defence, it was one of the tougher heats with Zimbabwe's Young Talkmore Nyongoni (45.92) and Belgian Cedric van Branteghem (45.94) also involved.