The Cork woman – the sole European representative in the final – had the Olympic champion, Dawn Harper (USA), the Olympic silver medallist and the fastest woman out here, Sally McLellan (Australia), behind her when she crossed the line.
And for one brief moment, at the fourth hurdle, she had the whole field trailing after producing what must be rated as the best start of her career.
I knew I was first to the fourth hurdle,” she said. “Then the middle was a little bit ropey and I knew that too.
“But my start has been awful all summer and we really worked on that for the past two weeks. I was worried because we had not done very many hurdles but Sean (Cahill, coach) insisted that the start was where I was losing 10ths of seconds.
“But right now I am top four in the world. In the past when I have finished fourth I have always built on it so well. It’s a national record. It has taken me three years to get back to this territory. I have to be incredibly happy.
“Fourth in the worlds – imagine if you told me that last year at the Olympics I would have absolutely killed you for it.”
She had run her third fastest time ever to get through the first round, ground it out in the semi-finals when she had to run to within a hundredth of a second of her national record – 12.73 secs – behind Harper and McLellan to get through among the fastest losers and then threw caution to the wind in the final where she had lane one.
“I knew I had to run my socks off to make the final,” she said. “And then I did not want to be the person who is just a token lane in the final – I wanted to be there and represent myself really well and keep my head held high.”
She did just that as she disputed the lead up to the fourth hurdle and then came storming through in typical fashion to take fourth place behind Brigitte Foster-Hylton (Jamaica), 12.51 secs, Priscilla Lopes-Schliep (Canada), 12.54 secs and Delloreen Ennis-London (Jamaica), 12.55 secs.
Her 12.76 secs will open many doors for her once the Grand Prix/Golden League series resumes after the championships.
“I always say I think I am as good as anyone in the world on my day,” she said. “I strongly believe that.”
Last September she sat down with her coaches Sean Cahill and his wife Terri to put a programme together. Cahill is a former international high hurdler while Terri, nee Horgan, is a former long jump record holder.
“We sat down last September and I said I want to win a European indoor medal and be in the final of the world championships – if I’m in a world final I think I can win a medal – and at the time it was crazy.
“Maybe I only believed it 50 per cent but Sean and Terry always believed it. I am so lucky to have them, they are absolutely amazing, I mean Sean paid for his own flights and accommodation out here.
“He’s just a superstar to me and Terri’s at home with all the kids and she is analysing and texting and phoning after each round. They are just amazing people to have around.”
She admitted there were times when she was beginning to despair but her boyfriend – Olympic sailor Peter O’Leary, who also hails from Cork – came to the rescue.
“My boyfriend calls me a drama queen because I get really down when things go badly – I’m real emotional – and he just tells me I am being dramatic.
“He is so level-headed. He is so level about his performances and he has been so unbelievably good to me this season – he doesn’t know that much about athletics, but has been brilliant. He has held me together.”
And it is not going to end here. Last night, a bullish O’Rourke promised an attack on the national record for 100m.
“People don’t believe that I can run 100m but I can and I would like to try a couple of races at the bigger meets before the season ends,” she said.