Kournikova's injury blow

Kournikova had been in good form

Injury has forced Anna Kournikova out of the doubles event at the Bank of the West Classic in California.

The Russian pulled out of her semi-final match on Saturday with an abdominal strain.

She sustained the injury in practice before her 6-3 6-4 quarter-final loss to Venus Williams in the singles event on Friday night.

Kournikova enjoys winning feeling

She aggravated it further during that match and in a subsequent quarter-final doubles victory with her American partner Meghann Shaugnessy.

The pair were forced to withdraw from their match against top seeds Lisa Raymond and Rennae Stubbs.

Kournikova will be examined by doctors before a decision can be made concerning her participation in a tournament next week.

The Russian is scheduled to face American Alexandra Stevenson in the first round of the Acura Classic.

She had performed well in the singles event with back-to-back victories before the defeat to Williams.