Williams, seeded second, whipped Ekaterina Makarova 6-3, 6-2 in just 63 minutes in a second-round match. She won 60 percent of the match's points, despite two service breaks.
The win combines with the recent poor play of No. 1-ranked Dinara Safina, who lost to No. 226-ranked Zhang Shuai Monday, to assure Williams of returning to the world No. 1 spot in next week's rankings.
No. 8-seeded Jelena Jankovic, the China Open defending champion, was one of two seeded players to lose in Tuesday's 10 matches. Jankovic fell 4-6, 7-5, 6-2 to Peng Shuai, who advanced to a third-round pairing against Maria Sharapova. Sharapova got the other upset, beating No. 9-seeded Victoria Azarenka 6-3, 6-7 (5-7), 7-5.
Fourth-seeded Elena Dementieva stopped Melinda Czink 6-4, 6-4 and No. 7-seeded Vera Zvonareva blitzed Francesca Schiavone 6-3, 6-0.
Tenth-seeded Flavia Pennetta got past Kateryna Bondarenko 3-6, 7-5, 6-3; 12th-seeded Agnieszka Radwanska stopped Patty Schnyder 6-4, 6-1; No.
13-seeded Nadia Petrova slipped by Daniela Hantuchova 6-1, 2-6, 7-5; 14th-seeded Marion Bartoli beat Alisa Kleybanova 6-2, 6-3; and Maria Jose Martinez Sanchez defeated Vania King 6-4, 6-4 in the day's other matches.
Copyright 2009 by United Press International.