Lindsay Davenport fought her way into the fourth round of the Pacific Life Open in Indian Wells with victory over Meghann Shaughnessy on Monday.
The top seed came through 6-2 2-6 6-2 against her fellow American and will meet Viktoriya Kutuzova in the last 16.
World number 473 Kutuzova of the Ukraine upset 17th seed Amy Frazer of the USA 6-3 6-3.
Maria Sharapova moved comfortably into the next round with a 6-2 6-3 victory over fellow Russian Dinara Safina.
The day's action was dominated by a blustery wind that led to some below-par performances.
"It's no fun to play like that," Davenport admitted.
"It makes for pretty awful tennis. Fans obviously don't enjoy sitting out there, trying to watch in that wind.
"It took out any strategy. You were just hoping the ball went in."
Sharapova said: "The first three games were not very pretty.
"But after that when the points went a bit longer and the wind died down I was able to hit the ball in more."
The number seven seed will face Colombia's Fabiola Zuluaga, who crushed 2002 Indian Wells champion Daniela Hantuchova 6-3 6-2.
Mary Pierce beat highly-rated 15-year-old Nicole Vaidisova of the Czech Republic 6-4 6-4.