Tashkent, Uzbekistan – Russians Ksenia Pervak and Alla round wins on Wednesday.
The top-seeded Pervak notched a 6-3, 6-3 victory over crowd favorite Sabina Sharipova of Uzbekistan, while the sixth-seeded Kudryavtseva earned a 6-1, 2-6, 6-3 triumph over fellow Russian Vitalia Diatchenko.
Russian Valeria Savinykh eliminated the fourth-seeded Sevastova, 7-5, 3-6, 6-3 and will next meet Czech Eva Birnerova, who took out the seventh-seeded Rodina, 6-7 (4-7), 6-4, 6-1.
French qualifier Victoria Larriere came up with her second straight win in the main draw with a 6-4, 6-4 victory over the fifth-seeded Rybarikova. She'll meet Pervak in Thursday's quarterfinals.
Kudryavtseva, the reigning Tashkent champ, will face Romania's Sorana Cirstea in the quarters. Cirstea, the 2008 Tashkent champ who beat second-seeded Bojana Jovanovski in the first round, advanced Wednesday with a 6-3, 6-4 win over Serbian qualifier Aleksandra Krunic.
The other quarterfinal will feature Greek veteran Eleni Daniilidou and Poland's Urszula Radwanska. Daniilidou toppled Japan's Misaki Doi, 7-6 (7-5), 6-4, while Radwanska rallied past Uzbekistan's Akgul Amanmuradova, 6-7 (2-7), 6-4, 6-3.
The newest Tashkent champion will collect $37,000.