Emma Navarro had full belief she would win her US Open quarter-final against Paula Badosa in straight sets.
The American 13th seed followed up her fourth-round win over defending champion Coco Gauff with a 6-2 7-5 success over the Spaniard to reach a grand slam semi-final for the first time.
It looked certain to go the distance, however, as Badosa was 5-1 up in the second set.
However, Navarro sensed Badosa would wobble and she went on to win 24 of the last 28 points in the match.
Ireland v England: TV details, kick-off time, team news and more
Italian sprinter Alessandro Ossola fails to qualify for final but has win with proposal on track
Ken Early: Manchester United fans losing patience as familiar flaws are evident again
Six championship matches, free to air on TG4, would be a gift from the GAA to itself
“Even though she was up 5-1, after that game, I felt like she wasn’t totally confident in her ability to close out that set,” Navarro said.
“I felt like if I could push back a little bit and make her think a little bit on her service game, maybe I could sneak my way back in there.
“Sometimes you’re out in the court, and you can picture yourself playing a third set.
“When I was out there, I didn’t picture myself playing a third set.
“I felt I could come back and do it in two.”
Badosa, who is still making her way back from a serious back injury, described her performance as a “disaster” and suggested the pressure of the occasion got to her.
“I think she played really good and she managed the situation really well, and I was a complete disaster,” Badosa admitted.
“The thing that makes me the way I am today, it’s a slam and your dream is always to make the last rounds in a slam.
“Performing the way I performed today, I know that if it wasn’t a slam I would perform well.
“So that’s what’s a little bit why I’m like this today, you know.
“Because I didn’t know how to handle it the best way. Now I have to wait four months for the next slam, so it sucks.”
Navarro will play favourite Aryna Sabalenka or Olympic champion Qinwen Zheng, with whom she had a spat in Paris, in the next round. – PA