World No. 105 Croatian–American Bernarda Pera reached her second WTA Tour semifinal by upsetting third-seeded Wang Qiang of China at the Prague Open on Thursday.

Pera secured her 6-0, 6-7 (5), 6-3 win against Wang on the clay court. The two met in March at the Indian Wells' hard courts where Wang had a 7-6(5), 6-2 victory over the 24-year-old.

It was only the Pera's second career victory over a top-20 ranked player and earned her a meeting with another surprising semifinalist, Karolina Muchova. The Czech player, who was given a wild card for the tournament, eliminated Russia's Natalia Vikhlyantseva 6-3, 6-4 to advance to her first WTA semifinal.

In an all-Czech quarterfinal, ninth-seeded Barbora Strycova eased past No. 6 Katerina Siniakova 6-1, 6-2, improving her record against her countrywoman to 4-1.

Swiss qualifier Jil Teichmann also reached her first WTA semifinal by knocking out Germany's Tamara Korpatsch 6-2, 6-1.