Reigning champion Serena Williams and second-seeded Victoria Azarenka were easy second-round winners, while Sara Errani became the highest-seeded loser thus far at the U.S. Open.
The world No. 1, four-time U.S. Open titlist Williams blitzed Kazakhstan's Galina Voskoboeva 6-3, 6-0 in 69 minutes at Ashe Stadium in a match that was postponed because of rain on Wednesday.
Williams has lost only four games through two matches this week.
"I'll have to think about it and see what I can do better, but it was OK," she said.
The reigning U.S. and French Open champ beat reigning Australian Open queen Azarenka in last year's finale in New York. The 16-time Grand Slam champion Williams is also a two-time runner-up in Flushing.
Up next for Williams will be another Kazakh, Yaroslava Shvedova.
Azarenka advanced to the third round in similar fashion, taking down 2009 U.S. Open runner-up Aleksandra Wozniak 6-3, 6-1. The former world No. 1 and reigning Aussie Open champ offered just 19 unforced errors and was not aced on her way to victory.
"It was a good match I think," said Azarenka. "Towards the end I felt like I let her play a little bit and she really went for her shots, so I had to adjust a little bit better."
Meanwhile, Flavia Pennetta sent her fourth-seeded fellow Italian Errani packing 6-3, 6-1 Thursday at the USTA Billie Jean King National Tennis Center. The 31-year-old Pennetta reached three U.S. Open quarterfinals from 2008-11 before missing last year's edition of her best Grand Slam event due to a right wrist injury.
"I tried to play aggressive from the very beginning and I was perfect today, I think," Pennetta said.
The 26-year-old Errani, who was the French Open runner-up and a U.S. Open semifinalist last year, has now lost four times in six meetings with Pennetta.
"I don't want to play. I don't want to stay out there on the court," Errani said following her lopsided setback against Pennetta.
In the final match of the evening, veteran Slovak Daniela Hantuchova defeated 17-year old American Victoria Duval, 6-2, 6-3. Duval, who won her first ever match at the Open on Aug. 27 when she shockingly knocked off 2011 Open champ and 11th-seeded Samantha Stosur, had 27 unforced errors compared to just 18 from her counterpart.
Sixth-seeded Caroline Wozniacki dropped just three games in taking down Russian Chanelle Scheepers 6-1, 6-2 while seventh-seeded former Wimbledon champion Petra Kvitova drubbed Serb Bojana Jovanovski 6-2, 6-4, and eighth- seeded German left-hander Angelique Kerber held off promising Canadian Eugenie Bouchard 6-4, 2-6, 6-3.
Resurgent Serb Jelena Jankovic, seeded ninth at this fortnight, whipped Russian Alisa Kleybanova 6-3, 6-2, and 10th-seeded Italian Roberta Vinci overcame Czech Lucie Safarova 4-6, 6-1, 6-2. The 24-year-old Kleybanova returned to the WTA earlier this month after battling Hodgkin's lymphoma, a form of cancer, over the last two years.
The French Open quarterfinalist Jankovic is a former world No. 1 who lost to Williams in the 2008 U.S. Open finale.
Former world No. 1 Ana Ivanovic blasted Romanian Alexandra Dulgheru 6-2, 6-1, while Wimbledon runner-up Sabine Lisicki, seeded 16th in Flushing, drilled Argentine Paula Ormaechea 6-2, 6-3. The Serbian star Ivanovic is a former French Open champ who reached her first-ever U.S. Open quarterfinal last year.
Hot 21st-seeded Romanian Simona Halep continued her recent winning ways with a 6-2, 6-1 rout of Croat Donna Vekic. Halep headed to New York having captured titles at four of her previous seven events, including last week in New Haven where she upset the 2011 Wimbledon titlist Kvitova in the final.
In some other second-round action involving seeds, No. 14 Russian Maria Kirilenko won 6-3, 6-1 over Portuguese Michelle Larcher De Brito, Japan's Kurumi Nara surprised No. 19 Romanian Sorana Cirstea 7-5, 6-1; Italian Karin Knapp upended No. 22 Russian Elena Vesnina 6-1, 6-4; No. 24 Russian Ekaterina Makarova doused American Bethanie Mattek-Sands 6-4, 6-4; No. 25 Estonian Kaia Kanepi dismissed Slovak Anna Schmiedlova 6-4, 6-1; No. 26 Alize Cornet of France subdued Croat Ajla Tomljanovic 6-2, 6-2; and No. 27 Russian Svetlana Kuznetsova held off Chinese Peng Shuai 6-1, 4-6, 6-4. The former top-five star Kuznetsova captured the U.S. Open title in 2004 and was the runner-up in New York in 2007.
American Alison Riske posted an upset by taking out 28th-seeded German Mona Barthel 6-4, 6-2. Riske's third-round opponent will be the formidable left- hander Kvitova.
Additionally, American Christina McHale bested Ukrainian Elina Svitolina 6-4, 3-6, 7-5, Israeli Julia Glushko upended American Sachia Vickery 7-5, 6-3, Italian Camila Giorgi swept Taiwanese Su-Wei Hsieh 6-4, 7-6 (10-8) and the aforementioned Shvedova handled Austrian Patricia Mayr-Achleitner 6-2, 6-3. The 21-year-old New Jersey native McHale will face Ivanovic in the round of 32.