The 26-year-old missed out on the Olympic 400 metres hurdles final in London 12 months ago after a disappointing showing in her semi-final in front of a vocal home support.
But, since then, Child has enjoyed a superb 2013, breaking the Scottish record twice already, and she showed that form in her Moscow semi, clocking 54.32 seconds to take third and claim a place in the final.
There, Child will be joined by her fellow Briton and medal favourite Perri Shakes-Drayton, who edged her into silver over the flat 400m earlier this year at the European Indoor Championships.
Shakes-Drayton qualified second fastest for the final at the World Championships in Moscow while Child was ranked fifth quickest over the two semi-finals. And, after the British pair both crashed out in the semi-finals at London 2012, Child could not hide her relief after making her first individual World Championship final.
“I’m delighted to make my first global final, I’m so happy because I wanted it so much,” she said. “This definitely makes up for London. I’m delighted.
“I was really quite nervous again before the race because I knew that I could do it. I can sleep well now before Thursday knowing that I have done it.
“It was messy again, like the heat, and I was actually surprised by how fast it was so if I can just get it even better again and beat my personal best, then I will be delighted. I want to come off and have run my best race in the final when it matters.”
Child went out so hard in her semi-final that she led the race after 300m, but that initial burst appeared to take a lot out of her as she faded to third in the home straight.
But her time of 54.32 was only one tenth of a second outside her personal best and she knows that if she can time her race better, then a podium place in Moscow is not out of reach.
“I didn’t intend to go out quite as fast as I did. I think adrenalin got the better of me a little bit but I wanted to go out and attack it from the start,” she added.
“I didn’t actually realise I was still leading after 300m but my hurdle eight to nine was not great. It’s given me a real boost that I can really contend and be up with these girls if I can get my race right. Anything can happen in the final so, hopefully, I can run well.”
Meanwhile, fellow Scot Eilish McColgan put in a brave effort in the 3000m steeplechase final. She was unable to repeat her heroics from the heat and set another new national record, but could be satisfied at coming home tenth in 9:37.33minutes.
Her mother and coach Liz, who won world 10,000m gold in 1991, described her daughter’s achievement as “a great building block for next year” on Twitter.
Elsewhere, Great Britain’s 400m hurdles men all bowed out of their semi-finals – including defending world champion Dai Greene – while Andrew Osagie finished fifth in the 800m final and Hannah England progressed into the 1500m final.
Robbie Grabarz successfully booked his spot in the high jump final, while Mo Farah – fresh from winning 10,000m gold on Saturday – is eyeing up a double in the 5,000m after breezing into the showpiece.
“The 5,000m was all right. I just wanted to do as little work as possible,” Farah said. “I wanted to freshen my legs up and just get ready for the final and I did that. I feel all right, the team and the physio have been looking after me and, other than that, I have just been resting up.
“This is just prelims, which is always going to feel harder. You know you have got to get up early in the morning and I’m not a morning person.
“But you have to deal with it, get it out the way and I knew the top five qualified so I just saved as much energy as possible.”
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