Wie started with two one-putt birdies to go 2 up against Melissa Martin of Altadena, Calif., lost three of the next five holes to go one down and then used three more one-putt birdies for a 3 and 1 victory.
The match wasn't clinched until the par-3 17th when Martin, already 2 down, hooked her drive into deep rough and couldn't get up and down.
Wie, 15 feet from the hole, two-putted to reach the third round.
The 14-year-old defending champion plays fellow Curtis Cup team member Jane Park in the afternoon. Park, 17, of Rancho Cucamonga, Calif., beat Kristen Campos of Mesa, Ariz., 5 and 3, in her second-round match.
Other early winners included medalist Brittany Lang of McKinney, Texas, 3 and 2 against Jenny Suh of Fairfax; In-Bee Park of Eustis, Fla., 4 and 3 against Lehua Wise of Lihue, Hawaii; and No. 2 qualifier Jenna Pearson of Wheaton, Ill., 1 up over Shannon Johnson of Sioux Falls, S.D.
Among the second-round losers were 14-year-old Stephanie Kono, a rising ninth grader at the same Punahou School that Wie attends in Honolulu, 2 and 1 to Hannah Jun of San Diego, and Carling Cho of San Juan Capistrano, Calif. She lost 4 and 3 to Hwanhee Lee of Los Angeles.
Wie, who has battled an uncooperative putter all week here, seemed to have put it all together at the start. She rolled in a 16-foot birdie putt on the first hole and a 5-footer for birdie on the second to go 2 up.
But when she started needing two putts on every green, Martin took advantage with one-putt birdies on three of the next five holes.
Wie tied it with a 2-footer on No. 8 after a dazzling shot from the rough about 50 yards out, went ahead with a 9-foot putt on No. 13 after outdriving Martin by 70 yards on the 345-yard par 4, then doubled her advantage at the par-5 15th after hitting her chip to about 30 inches.
'I was proud of myself,' Martin said. 'I knew she wouldn't give me too many, and she didn't, and that's the way a match should be.'
At just 5-foot-3, Martin was almost dwarfed by the 6-foot Wie, but was thrilled to learn when she arrived Friday that they had been paired.
'David and Goliath,' she said, laughing.
Copyright 2003 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.