French Open champion Barbora Krejcikova marched through to the Prague Open semi-finals following a straight-sets victory over doubles partner Katerina Siniakova.
The in-form second seed has six titles to her name this season; three of which have come alongside Siniakova in doubles events.
Together, they have triumphed at Roland Garros – adding to Krejcikova’s singles success – as well as in Madrid and the Gippsland Trophy.
However, this was their first singles meeting at Tour level, which went with the form book as Krejcikova claimed her 18th win in 19 matches after comfortably prevailing 6-3 6-0.
The home favourite, who is still to drop a set in the Czech capital, will play Wang Xinyu in the semi-finals after the world number 147 beat Grace Min 6-3 6-3.
Meanwhile, eighth and ninth seeds Tereza Martincova and Greet Minnen will face off in the other semi after straight-set wins over Viktoria Kuzmova and Storm Sanders respectively.
At the Lausanne Open, Roland Garros semi-finalist Tamara Zidansek is through to the last four; the top seed beating world number 241 Lucia Bronzetti 6-4 4-6 6-3.
Fifth seed Caroline Garcia overcame Zarina Diyas 7-5 6-2, but second seed Fiona Ferro lost by the same scoreline against world number 125 Clara Burel.
Elsewhere, top two seeds Yulia Putintseva and Danielle Collins remain on course to meet in the Hungarian Grand Prix final.
Putintseva needed three sets to see off Kateryna Kozlova 6-7 (4-7) 6-0 7-5, while former Australian Open semi-finalist Collins overcame Argentina's Paula Ormaechea 6-1 6-4.