Kellee Booth advanced to the semifinals in Asheville, N.C.
The nation's top-ranked amateur, who has five victories this season, had to rally for the third time in four matches at Biltmore Forest Country Club after falling two holes behind in the early stages against Stanford's Stephanie Keever.
Booth, 23, a former Arizona State star expected to turn pro after this event, rallied with birdies on Nos. 8-10 _ missing a hole-in-one on No. 9 by inches _ to pull even in her match.
Booth went 2-up with another birdie at the par-5 13th and closed out Keever with a 20-foot par putt on the 17th to win 2 and 1.
"I don't feel any pressure being expected to win," said Booth, who had a combined nine birdies in her two victories. "I have just been playing really well so I guess people expect me to win. I'm going to try to keep the momentum going."
Booth takes on Dorothy Delasin, a 2-and-1 winner over Jennifer Hubbard, today.
Teenager Lorena Ochoa, who had to play just a combined 25 holes in winning twice Wednesday, continued her strong play with 2-and-1 victories over 45-year-old veteran Robin Weiss, the No. 3 ranked amateur, and Michigan State's Kasey Gant.
Ochoa faces Jimin Kang today.
AJGA'S CANON CUP: The West team ended the East's bid to win its sixth straight title by winning the final four singles matches at Hilton Head Island, S.C.
For the East, Tampa's Whitney Code won her match 2 and 1 and St. Petersburg's Michael Barbosa lost 1-up.