The American tennis player Serena Williams is set to lose her world number one ranking to the women she beat in the US Open just three weeks ago Serbia's Jelena Jankovic.
This follows her stunning collapse in the second round of the Stuttgart Grand Prix in Berlin to China's Li Na love-six, 6-1 6-4 today.
Earlier, Switzerland's Patty Schnyder beat fifth-seeded Russian Svetlana Kuznetsova 6-4 4-6 7-5. Schnyder is seeking her second title of the year after winning in Bali.
Seventh-seeded Vera Zvonareva advanced to the second round by beating Daniela Hantuchova of Slovakia 6-3 6-2.
Russia's Zvonareva won Olympic bronze in Beijing and also won in Guangzhou, her second title of the year.
