BEIJING, Sept. 13 (UPI) -- Top-seeded Nikolay Davydenko was knocked out of the $500,000 China Open tennis tournament with a straight-set defeat Thursday in second-round play.
Davydenko, a semifinalists at the U.S. Open, was ousted in a 6-3, 6-4 decision by Marin Cilic in the hard-court tournament.
Cilic earned a quarterfinal berth against wild-card entry Nicolas Kiefer, who posted his own second-round upset with a 6-3, 6-4 win over seventh-seeded Jo-Wilfried Tsonga.
Two seeded players did mange to advance out of the second round Thursday. No. 3 Tommy Robredo defeated Rik De Voest 6-2, 6-3; and eighth-seeded Igor Kunitsyn topped Kevin Kim 7-6 (7-4), 6-4. Robredo and Kunitsyn are paired against each other in the quarterfinals Friday.
The other quarterfinal matches send second-seeded Fernando Gonzalez against sixth-seeded Lee Hyung-taik and No. 4 Ivan Ljubicic versus fifth-seeded Marcos Baghdatis. Baghdatis is the tournament defending champion.