Top seed Karolina Pliskova survived a second-set wobble to book her place in the semi-finals of the J&T Banka Prague Open.
The Czech player saw off compatriot Denisa Allertova 6-2 5-7 6-1.
But third seed Barbora Strycova crashed out as she went down to fellow Czech Katerina Siniakova 6-4 6-2.
Lucie Hradecka made it three home players in the last four with a 7-5 4-6 7-5 success over Klara Koukalova, while Belgium's Yanina Wickmayer completed the semi-final line-up thanks to a 2-6 6-3 6-3 victory over Danka Kovinic of Montenegro.
In the last four Pliskova will take on Wickmayer and Siniakova will be up against Hradecka.
Source: PA
