The victories mean Jankovic and Davenport will face each other in Friday’s quarterfinals. Jankovic, ranked No. 3 in the world, will be a strong test for Davenport, who is playing her first singles tournament in about a year and who had her first child in June.
Davenport has played well this week, as shown by her 6-1, 6-4 pasting of Julie Ditty on Thursday. Jankovic had only a little more trouble in eliminating Casey Dellacqua, 6-1, 6-4.
Also, seventh-seeded Aiko Nakamura defeated Youlia Fedossova, 6-2, 6-2.
Second-seeded Daniela Hantuchova is to play Ayumi, while Nakamura is paired against Errani and Cirstea is to meet Edina Gallovits in the other quarterfinal matches Friday.