Top seed Anastasija Sevastova crashed out of the Bucharest Open in straight sets to unseeded Ana Bogdan.
Romanian Bogdan took just over an hour to dispatch the Latvian 6-1 6-3 and register her first victory over a top-20 player.
She will face Germany's Julia Goerges, a 7-5 7-5 winner over Russia's Ekaterina Alexandrova , in the semi-finals.
Bogdan's compatriot Irina-Camelia Begu, seeded seventh, won 10 games in a row to defeat France's Pauline Parmentier 7-5 6-0.
Begu will meet second seed Carla Suarez Navarro of Spain, who beat Germany's Tatjana Maria 6-0 6-3.
At the Gstaad Championship in Switzerland, Dutch second seed Kiki Bertens was a 6-4 6-4 winner over Swede Johanna Larsson.
Standing in her way of a place in the final is Spain's Sara Sorribes Tormo, who beat Tamara Korpatsch of Germany 6-2 6-3.
Sixth seed Anett Kontaveit of Estonia sank Germany's Carina Witthoeft 6-2 6-4 and meets Czech Tereza Martincova - who overcame Antonia Lottner of Germany 3-6 6-1 7-5 - in the last four .
Source: PA
