Ana Bogdan stunned top seed Anastasija Sevastova in the Bucharest Open quarter-finals, while Kiki Bertens booked a place in the last four of the Ladies Championship Gstaad.
Romanian Bogdan delighted the home crowd with a surprise 6-1 6-3 victory over Sevastova - the Latvian failing to prove worthy of her 91-place advantage in the world rankings.
Sevastova's exit makes Carla Suarez Navarro the highest remaining seed after she overcame Tatjana Maria 6-0 6-3 to advance to the semi-finals with another flawless display.
The Spaniard will take on another home hope in Irina-Camelia Begu after her defeat of Pauline Parmentier, while Bogdan's opponent will be third seed Julian Gorges - a 7-5 7-5 winner against Romanian qualifier Alexandra Dulgheru.
In Switzerland, second seed Bertens triumphed in the standout clash, denying Johanna Larsson a spot in the semi-finals with a 6-4 6-4 victory.
The Dutchwoman will take on Sara Sorribes Tormo, who beat Tamara Korpatsch 6-2 6-3, in the semi-finals, while Anett Kontaveit ousted Carina Witthoft 6-2 6-4.
Tereza Martincova stands between Kontaveit and the final after she defeated German qualifier Antonia Lottner 3-6 6-1 7-5.