Wu started Tuesday’s second round of stroke-play qualifying with a bang, sticking her 8-iron tee shot at the par-3 10th to 5 inches. She bogeyed the ensuing hole, but proceeded to birdie three of her next four holes. At one point, Wu had reached 5 under and held a three-shot lead. Wu, who has committed to UCLA for the fall of 2015, finished with a 2-under 68 to finish one stroke ahead of first-round leader Su-Hyun Oh, of Australia, and Andrea Lee, 15, of Hermosa Beach, Calif.

“Going to the back nine, I was thinking, ‘Don’t make any mistakes,’” said Wu, the runner-up at last week’s Junior PGA Championship and a quarterfinalist two weeks ago at the U.S. Girls’ Junior in Flagstaff, Ariz.

Wu did make a few mistakes, as consecutive bogeys at Nos. 7 and 8 saw her lead trimmed. But Wu closed out with a par at the ninth to earn the top seed for the 64-player match-play draw.

“(Earning medalist honors is) good for me because I’ve beat really top players here through stroke play,” said Wu.

Lee and Oh tied for second at 2-under 138. Lee double-bogeyed the par-4 11th (her second hole), but more than made up the deficit with three birdies on her second nine, finishing at 69. Oh, 19, carded three bogeys and a birdie for a 72.

Four players tied for fourth at 140: Dylan Kim, 17, of Plano, Texas; Celine Boutier, 20, of France; Alison Lee, 19, of Valencia, Calif.; and Megan Khang, 16, of Rockland, Mass.

Defending champion Emma Talley needed a major second-round comeback to ensure her title defense would continue. After a 6-over 76 on Monday, Talley, 20, of Princeton, Ky., returned an even-par 70 to easily advance.

“I knew that today was a big day,” said Talley, who converted the winning putt for the USA at June’s Curtis Cup Match at St. Louis (Mo.) Country Club. “I got 1 over at one point, and I knew I just needed to stick with my game.”

Talley admitted to losing some control of her driver during the round, saying she was “blowing out” on occasion. She opted to leave the club in the bag on her inward nine, relying on her 3-wood instead.

Local favorite Annie Park wasn’t so fortunate. The 19-year-old from Levittown, N.Y., missed the cut after shooting a 7-over 79 to finish at 9-over 149, one stroke off the match-play cut. Admitting to putting struggles, Park, the 2013 NCAA Division I champion and a 2014 USA Curtis Cup player, made five bogeys as well as a double-bogey-6 at the 14th.

“I couldn’t make any putts, so then I had more pressure into my shots to get it closer,” said Park. “But obviously that’s not going to work.

“Toward the back, I was trying to get it back together, but nothing was falling in. It was just that day.”

Karah Sanford, 12, of Escondito, Calif., birdied her final two holes to earn a berth in the match-play bracket. Sanford, the youngest player in the Women’s Amateur field, becomes the fourth 12-year-old to advance to match play, joining Pearl Jin (2007), Lexi Thompson (2007) and Hannah O’Sullivan (2011). Thompson advanced the furthest, reaching the quarterfinals.

Notables to miss the cut include four-time U.S. Women’s Mid-Amateur champion Meghan Stasi (149), 2013 U.S. Girls’ Junior champion Gabriella Then (155), six-time USGA champion and 2014 USA Curtis Cup Captain Ellen Port (156), 2014 U.S. Women’s Amateur Public Links champion Fumie (Alice) Jo (157) and 2011 U.S. Women’s Mid-Amateur champion Martha Leach (158).

The cut came at 8-over 148, leaving an 8-for-3 playoff to determine the final match-play qualifiers. Two holes were completed before play was suspended due to darkness, with three players eliminated. Michelle Piyapattra, Mariana Sims, Haylee Harford, Lakareber Abe and Mary Chandler Bryan will resume the playoff Wednesday at 7:15 a.m. EDT.

The 2014 U.S. Women’s Amateur Championship consists of 36 holes of stroke play followed by six rounds of match play. The championship is scheduled to conclude with a 36-hole final at 8:30 a.m. EDT on Sunday.

The U.S. Women’s Amateur is one of 13 national championships conducted annually by the United States Golf Association, 10 of which are strictly for amateurs.