Karolina Pliskova of the Czech Republic made a winning start to her defense of the Malaysian Open title by easing past Aleksandra Krunic 6-2, 6-2 in the first round on Tuesday.
Venus Williams upset top-seeded Victoria Azarenka 6-2, 6-4 on Tuesday to advance to the third round of the Pan Pacific Open.
Angelique Kerber of Germany advanced to the third round of the Pan Pacific Open by beating Maria-Teresa Torro-Flor 6-0, 6-1 Monday.
Ayumi Morita of Japan pulled out of the U.S. Open on Sunday because of a lower back injury.
Carla Suarez Navarro used a strong return game for a 6-4, 6-3 win over Sachie Ishizu in the first round of the Southern California Open on Tuesday.
American teenager Madison Keys beat No. 8 seed Magalena Rybarikova 6-2, 6-2, in the first round of the $795,000 Bank of the West Classic on Monday.
Melanie Oudin's defense of her Aegon Classic title lasted only 57 minutes Monday, with the American losing 6-3, 6-1 to Croatian qualifier Ajla Tomljanovic in the first round.
Seventh-seeded Sara Errani advanced to the second round of the Madrid Open, beating Urszula Radwanska of Poland, 6-3, 6-1 on Saturday.
Ekaterina Makarova and Elena Vesnina won the decisive doubles match Sunday as Russia completed a comeback victory over Slovakia to reach the Fed Cup final.
Sara Errani and Roberta Vinci gave Italy a 2-0 lead over the two-time defending champion Czech Republic in the Fed Cup semifinals on Saturday.
Bethanie Mattek-Sands of the United States defeated third-seeded Anastasia Pavlyuchenkova of Russia at the Malaysian Open to reach her first WTA singles final in two years.
Fourth-seeded Ayumi Morita of Japan defeated Thailand's Luksika Kumkhum 6-7, 6-4, 6-1 Friday to march into the Malaysian Open semifinals.
Defending champion Hsieh Su-wei won two matches Thursday to reach the Malaysian Open quarterfinals.
Top-seeded Caroline Wozniacki has lost to Wang Qiang 2-6, 7-6 (1), 6-1 Wednesday in the first round of the Malaysian Open.
American Varvara Lepchenko won in her Fed Cup singles debut to lift the United States to a 1-1 tie against Italy on Saturday.
Second-seeded Maria Kirilenko of Russia reached the Pattaya Open semifinals by beating Elena Vesnina 7-6 (6), 6-3 Friday.