Updated

MOSCOW (Reuters) - The Kremlin Cup suffered a double blow on Wednesday when top seed Nikolay Davydenko was beaten in his opening match while champion Mikhail Youzhny was forced to pull out with a virus infection.

"I had made a decision to withdraw after losing my doubles match," Youzhny, seeded second, told reporters.

"I don't feel well at all and I don't think I would have been able to play the singles in such condition.

"I will now have to take a break from training for a few days and see how I feel," added the world number nine, still with a chance to qualify for the World Tour Finals in London next month.

"I'm scheduled to play next week in St Petersburg but right now I'm not sure if I'll be able to be there. I'll have to make a decision by the end of the week."

Davydenko, who like his Russian compatriot Youzhny had a bye in the first round, lost his opening match for the second week in a row, going down to Uruguay's Pablo Cuevas 7-6 7-6.

STRUGGLING DAVYDENKO

"Usually I could dominate a player like Cuevas with my speed and power from the baseline," said Davydenko, who has recently struggled to find the kind of form that helped him to win the season-ending World Tour Finals in London last year.

"Tonight, I didn't have the speed nor the power in my legs."

Wednesday's double setback has added to the disappointments of the home crowd and local organizers of the annual ATP and WTA tournament that had been decimated by the withdrawals of high-profile players, particularly on the women's side.

Russians Vera Zvonareva, Svetlana Kuznetsova and Maria Sharapova and 2009 champion Francesca Schiavone all pulled out.

Serbia's eighth seed Janko Tipsarevic, who lost to Youzhny in last year's final, was bundled out in the first round on Wednesday by Horacio Zeballos 4-6 6-4 6-3.

On the women's side, second seed Victoria Azarenka of Belarus beat Germany's Andrea Petkovic 6-4 2-6 6-1 and eighth-seeded Spaniard Maria Jose Martinez Sanchez saw off Ukraine's Alona Bondarenko 6-4 1-6 6-1 to reach the last eight.

(Reporting by Gennady Fyodorov; editing by Pritha Sarkar)