Susan Smith is ready to push herself harder than at any time in her career to justify her inclusion among the eight athletes who will contest the world 400 metres hurdles final this evening. In making the transition from "journeyman" athlete to prime championship contender, the 26year-old Waterford woman has earned a reputation as a tough, abrasive competitor who spares nothing or nobody. But she knows she is now going to have to dig deeper, hurt more, than at any time since she resolved to challenge the best in the world. "I know I'm going to hurt, but I've never had a problem with pain," she said. "The last 20 metres of every race, when you're almost out on your feet, are painful. This time, the pain barrier will come much earlier but I'm ready for it.

"For me it's a big occasion, so big and so exciting that I didn't sleep after the semi-final. But I'm still going to enjoy it."

Against all the odds, the woman who didn't rate a place in the top 150 in the world 18 months ago has earned the right to line up with seven of the biggest names in one of track's most punishing events. And, having consistently defied sporting logic since beginning her ascent through the rankings, who is to say that she is not capable of more? Certainly, not the athlete herself. "I've got to believe that if I work hard enough and run to the very limit of my potential, I have a chance," she said. "My goal coming here was to reach the final. Now the target is to get the highest place I can against the best in the world."

Smith's hurdling technique is already one of the best in the event, a point acknowledged by international commentators. In two races here, her only blemish was when she brushed the eighth hurdle in the semi-final after being forced to chop her stride. Long since freed of the injury problems which at one point threatened her career, the only pressures which now bear on her are self-imposed. And the prospect of meeting Kim Batten and Deon Hemmings, among others, is not overly intimidating. Batten, who finished in front of her in both her races here, derives most of her incentive these days from the thought of re-establising herself as the number one hurdler after winning the world title and setting a world record in the process at Gothenburg two years ago. That accolade has since passed to the Olympic champion, Deon Hemmings, after her fluent success in Atlanta and, judged on her elegance in winning both her heat and semi-final races, the Jamaican is entitled to start as favourite.

The only other Irish competitor in action today is Mark Carroll. The 25-year-old Cork man who is embarked on a comeback in the 5,000 metres this summer after having to miss out on the Olympic Games because of a recurring ankle injury.

Carroll runs in the second heat of the 5,000 metres this evening and will be encouraged by the fact that the graph of his season is on the climb after two fine performances at meetings in Linz and Hechtel. A 3:53.82 mile at Linz was the prelude to a fine 5,000 metres run in 13:14.06, the second fastest of his career, which has boosted his chances of reaching the final here on Sunday.

Bob Tisdall, Ireland's 1932 Olympic 400 metres hurdles champion, will be cheering on Smith from his native North Tipperary home tonight. The Los Angeles champion, who has lived in Australia since the 1950s, is back in Ireland for a three-week holiday at the Dromineer, Nenagh, home where he was raised.

Tisdall (90), the last Irish Olympic champion in a hurdles event, will be honoured by a welcome home party by the local club, Nenagh Olympic.