Top-seeded Simona Halep cruised into the semifinals of the Transylvania Open on Friday, but U.S. Open champion Emma Raducanu lost to a fellow teenager in less than an hour.
The third-seeded Raducanu lost 6-2, 6-1 to 19-year-old Marta Kostyuk of Ukraine after struggling with her serve throughout the match. Raducanu double-faulted seven times and won less than half the points in her service games as Kostyuk advanced to her third semifinal of the season.
Kostyuk will aim to reach her first career final when she plays Halep, who eased past fellow Romanian player Jacqueline Cristian 6-1, 6-1.
No. 2-seeded Anett Kontaveit also had a smooth path into the semifinals, beating Anhelina Kalinina of Ukraine 6-3, 6-1 for her 13th straight indoor win, following titles in Ostrava and Moscow.
The win kept the second-seeded Estonian in the race for the season-ending WTA finals next month.
Kontaveit will play Rebecca Peterson of Sweden, who edged Lesia Tsurenko of Ukraine 6-2, 3-6, 6-3.