The Great Britain team captain finished third in the last of three semi-finals, outside the automatic spots, but her time of 55.33 was enough to achieve her stated pre-championship goal of reaching the final, albeit in the eighth and last spot.
Anything can happen, particularly when hurdles are involved, and Doyle is where she wants to be but, realistically, the days when the 30-year-old from Perth could harbour serious individual medal hopes at a major global championships are probably gone.
Her event is progressing at a rate of knots, led by the imperious Olympic champion Dalilah Muhammad, who won Doyle’s heat, with Sage Watson of Canada in second.
But the Scot, who will also be part of the British women’s 4x400m relay squad at the weekend along with flat 400 semi-finalist Zoey Clark from Aberdeen, exuded a sense of satisfaction after the race.
“The good thing was that I was in the last semi so I didn’t have to wait, unlike in Rio [Olympics last year] when I was in the very first one,” said Doyle.
“I saw the results of the first two semis so I knew the times didn’t seem to be too fast out there tonight. I just thought that obviously I wanted to get top two to secure that qualification, but I knew that if I could just try to run as fast as I could I could obviously try to sneak in.
“It’s always so difficult when it’s three semi-finals and I knew when I crossed the line that I’d be close to it.”
Double world champion Zuzana Hejnova went through as fastest qualifier on 54.59, with Muhammad fifth quickers on 55.00.
Running from the outside ninth lane, as she had in the heat, Doyle ran a focused race and reached the final bend in contact with Muhammad and Watson but couldn’t improve further despite a strong home straight.
“Lane nine has its pros and its cons. It means you don’t get caught up with what’s going on behind you,” she said. “In particular Dalilah’s a very fast starter and sometimes you can get caught up with her being ahead of her.
“So in lane nine I can kind of run my own race but obviously you need people next to me or it’s just like a training run and coming into the home straight that was the only time I could work out where I was.
“Hopefully I’ll get a better lane in the final, but if it’s lane nine I can’t complain.”
Doyle said she has been enjoying her captaincy duties and said: “Obviously it’s an individual sport so you switch to your own focus come the time but I’ve actually found it a good outlet to be chatting to the other athletes.”
For now, Doyle has yet another major final to look forward to.
“It is always a huge opportunity, but like I’ve said all year the hurdles has been wide open this year,” she said. “It’s been that close that you could run a PB and have not made the final or you could be in there and win a medal.
“With hurdles anything can happen and it’s just who executes the best race on that night, who gets the strides right, who nails the hurdling and who doesn’t make mistakes. When that happens it’s anybody’s and at least I’ve put myself in the final so that I can be in contention to do that.”
In tonight’s action, Scotland’s Andrew Butchart, who finished a superb sixth in the Rio Olympics last year, will go in the second heat of the 5,000m.
Mo Farah returns to the track following his opening night heroics in the 10,000m in the first of those heats as he seeks another double to round off his historic track career.
Lennie Waite is in the women’s steeplechase heats to kick off the evening’s action, while Chris Bennett is in the second group of the men’s hammer qualification.