Barbora Strycova will face Serena Williams in her first grand slam semi-final after shocking British hope Johanna Konta at Wimbledon.
The 33-year-old from the Czech Republic came from 4-1 down in the first set to win 7-6 (5) 6-1 on Centre Court.
Strycova's only other quarter-final appearance at a major tournament was here five years ago, but on Thursday she will get a shot at seven-time winner Williams for a place in the final.
"It sounds crazy. It's happening but I can't really believe it," she told the BBC.
"It was one of the best matches I've played here. I haven't been playing on Centre Court so it was a special moment.
"It's a great week to play (Williams) and a match I look forward to."
Williams proved she is battle-hardened after coming through a thrilling three-setter in the all-American showdown against Alison Riske to reach her 12th semi-final in 19 appearances at the Championships.
Riske, unseeded and ranked 55, had knocked out world number one Ashleigh Barty 24 hours earlier, and she pushed Williams all the way.
But for Riske there was no reward despite five breaks of serve – converting every single break point she created – against the 23-time grand-slam winner who won 6-4 4-6 6-3.
"I just needed to just fight," admitted Williams.
"Alison, I mean, she played great throughout the whole tournament. She's beaten so many amazing players, players that have had great years.
"She was not giving it to me. I needed to step up and take it. That's what I had to do."
Having been pegged back to 1-1 by the stubborn Riske, Williams seemed to find a second wind after tying her hair up, eventually wrapping up victory with her 19th ace.
"It was just in my way. I was missing a shot because it was in my face," she said.
"I was like, 'this is not happening'. I just needed to get it out of the way, put the business bun up and just get to business."
The second semi-final sees seventh seed Simona Halep face Elina Svitolina, seeded eighth.
Romanian Halep found herself 3-0 down in the opening set as China's Shuai Zhang briefly threatened a shock.
But Halep recovered to take the first set on a tie-break and then raced through the second to win 7-6 (4) 6-1.
Halep said: "I expected her to play so well, she beat me the last two times that we played.
"I was a little bit nervous before the match, a little bit stressed. I knew that she's going to come and hit the balls very strong.
Congratulations @Simona_Halep , you deserved the win and good luck in the rest of @Wimbledon https://t.co/AtZeyYWlPS — Shuai Zhang (@zhangshuai121) July 9, 2019
"Also when she hits them, the ball doesn't bounce that much. It's really tough to return.
"But I kept fighting. I knew that I have to be 100 per cent for every ball, then I will break her rhythm a little bit. It happened in the second set."
Ukrainian Svitolina was a 7-5 6-4 winner over Czech Karolina Muchova to advance to her first grand-slam semi.
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