ORDER OF PLAY
CENTRE COURT -- 11:00 a.m. start
Irina-Camelia BEGU (ROU) vs. Sara SORRIBES TORMO (ESP) (to be finished 6-2 0-1)
 Elise MERTENS (BEL) vs. Kristyna PLISKOVA (CZE)
 Simona HALEP (ROU) vs. Begu or Sorribes Tormo
 Barbora KREJCIKOVA (CZE) / Katerina SINIAKOVA (CZE) vs.  Monica NICULESCU (ROU) / Raluca OLARU (ROU)
Top seed Simona Halep is into her third semifinal of the season at the Prague Open. This year, Halep won her 20th career WTA singles title in Dubai and reached the semifinals at the Australian Open. Her only other tournament this year resulted in a quarterfinal showing in Adelaide.
Read more: Halep soars into Prague semifinals
World No.2 Halep has won seven WTA singles titles on clay. Only two active players have won more: Serena Williams (13) and Venus Williams (9).
Elise Mertens and Kristyna Pliskova will meet for the third time, with Mertens having a 2-0 lead in their head-to-head. Both of their previous encounters came on hardcourt last season, and the Belgian triumphed both times in straight sets, at Doha and the US Open.
Mertens is into her first semifinal of the season (her most recent one came at 2019 Osaka), and it is her first semifinal on clay since her title-winning run at 2018 Rabat.
Read more: Mertens edges past Bouchard in Prague
Pliskova is one win away from reaching her second Prague final, having finished runner-up in 2017. During that run three years ago, she defeated Jelena Jankovic and Jelena Ostapenko, before falling to Mona Barthel in the championship match.
Pliskova hit nine aces in each of her first two matches this week. She has hit 111 aces so far this season, the third-highest total on tour after Elena Rybakina (144) and Garbine Muguruza (122).
Rain postponed the remainder of Thursday's quarterfinal match between Irina-Camelia Begu and Sara Sorribes Tormo, and they will resume on Friday with Begu leading by a set. Begu had already finished off a darkness-delayed second-round match earlier on Thursday, when she defeated Leonie Kung in a three-and-a-half-hour epic that spanned two days.