Kim Clijsters moved a step closer to her first Grand Slam title with a 6-3 6-2 win over 27th seed Svetlana Kuznetsova of Russia.
The top seed now faces American Meghann Shaughnessy, who upset 13th seed Vera Zvonareva 4-6 6-4 6-2.
Shaughnessy, who advanced to the fourth round for the first time mixed her pace in the second set to derail her Russian opponent.
“I just kept telling myself to keep fighting,” Shaughnessy said. “The first set, she was controlling most of the rallies and running me around a lot.
“I just tried to change the momentum of the match a little bit. Then she let down a little bit, she got a little bit angry. I took advantage of that.”
Third seed Lindsay Davenport thrashed Hungary’s Melinda Czink 6-0 6-2 in 42 minutes to reach the fourth round.
The American is battling an injury in two toes on her left foot, but has yet to drop a set this week.
“It’s feeling better every day,” said the 1998 champion, who will undergo surgery after the tournament.
“The doctors say every day that goes by, the steroid injection kicks in probably a little bit more. I actually have not felt it since Monday morning.”
Davenport will play 19th seed Nadia Petrova in the next round after the Russian trounced 14th seed Amanda Coetzer of South Africa 6-0 6-1.
It was not a good day for the other Russian women as fifth seed Amelie Mauresmo of France cruised past 16-year-old qualifier Maria Kirilenko 6-4 6-2.
Mauresmo will face Tamarine Tanasugarn in the third round after the unseeded Thai crushed ninth seed Daniela Hantuchova of Slovakia 6-2 6-4.
Hantuchova committed 33 unforced errors as she suffered her third straight second-round loss in a Grand Slam.