BEIJING (AP) - Nikolay Davydenko cruised into the quarterfinals of the China Open with a 7-5, 7-5 win over Marin Cilic of Croatia on Wednesday.
The fourth-seeded Russian will face American John Isner, who beat Germany's Philipp Kohlschreiber 7-6 (3), 3-6, 6-3.
German qualifier Michael Berrer could not duplicate the play that helped him beat fifth-seeded Tomas Berdych in the previous round, falling to Gilles Simon of France 6-7 (6), 6-4, 7-6 (4).
On the women's side, Serbia's Bojana Jovanovski, who previously knocked out third-seeded compatriot Jelena Jankovic, lost to Shahar Peer of Israel 6-1, 6-2.
``I'm very happy. I was playing very well today, very aggressively,'' Peer said. ``I hope to keep going and play better and better every round this week.''
Angelique Kerber of Germany continued her strong play with a 6-2, 6-1 second-round victory against Romania's Alexandra Dulgheru.
Second-seeded Vera Zvonereva moved into the quarterfinals after defeating fellow Russian Maria Kirilenko 5-7, 6-4, 6-2.