Just as in her victory over Christina McHale in the previous round, No.2 seed Schmiedlova was forced to overcome a mid-match blip before finally prevailing, 6-4, 3-6, 6-1. Meeting the Slovak for a place in the final will be the tournament's surprise package, qualifier Aliaksandra Sasnovich.
"I think it was similar to my matches before, it was really tough and I had to fight in the end and play really, really well because she's a great player and played really aggressive," Schmiedlova said. "I didn't make many silly mistakes and I think this was the most important thing today.
"Perhaps it was my fault for not playing aggressive enough, but she made less mistakes and really served well in the second set. But I'm happy I came back and raised my game and played a really great third set."
It has been a year to remember for Schmiedlova, who is now on the cusp of the Top 30 following titles in Katowice and Bucharest and a number of reputation-enhancing showings elsewhere. It is all a far cry from 2014, during which she endured one particularly soul-searching slump in form.
"It's tough to say what has made the difference this year," Schmiedlova added. "I don't know what helped me, but I feel much more confident and believe in myself much more than last year. There was a tough part when I lost nine matches in a row, but I think I became stronger from that experience and I really feel good now."
Despite sitting over 100 places below Schmiedlova in the rankings, semifinal opponent Sasnovich will be no pushover, as she proved by knocking out No.3 seed Sloane Stephens, 6-3, 6-2.
On the other side of the draw, top seed Irina-Camelia Begu will face Alison Van Uytvanck. Begu has endured a couple of scares already this week and was once again made to work hard, eventually seeing off Johanna Larsson, 6-4, 7-5, while No.8 seed Van Uytvanck beat Elizaveta Kulichkova, 6-1, 4-6, 6-2.