Wie, the 14-year-old defending champion, led 5-up at the turn. She made three short birdie putts and won two other holes with two-putt pars.
After a break for lunch, Wie played Angela Park of Torrance, Calif., a 4 and 3 winner against Nara Shin of Chula Vista, Calif., for a spot in Sunday's 36-hole championship.
The other semifinal pitted Ya-Ni Tseng of Taiwan, a 7 and 5 winner against Hannah Jun of San Diego, against In-Bee Park, who birdied five of her last six holes in a 1-up, 22-hole victory against Brittany Lang.
Park, of Eustis, Fla., was 4-down after four holes in the first round, then beat Tiffany Tavee of Gilbert, Ariz., 1-up with an 18th-hole birdie. The only time she led against Lang was when she won.
'She's one of the best clutch putters I've ever seen,' Lang said.
Lang, the record-setting medalist from McKinney, Texas, led 2-up going into the 17th hole and then had an 8-foot putt to win on the par-5 18th. But her putt circled the hole and lipped out before Park hit a 6-footer.
Both players started the extra play with two birdies and a par on the rain-soaked Green Course at Golden Horseshoe Golf Club. Park won it with an 8-footer after Lang's sliding 15-footer didn't fall.
'The important thing is I didn't beat myself,' Lang said.
The match was the only tight one of the quarterfinals.
Wie took the lead on the par-4 third hole by sinking a 7-foot putt. She then made her save of the week, hooking her second shot into the par-5 fifth, taking a free drop away from a fence and sticking her chip to 6 feet, a putt she rolled in to go 2-up.
When Pearson three-putted the next hole, Wie went 3-up. An 8-foot birdie at No. 8 and two more three-putts by Pearson made it 6-up after 10. Four holes later, matching pars finished the match.
'You know she's not really going to drop a whole lot of shots and give you an opportunity,' Pearson said.
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