Ariya Jutanugarn

Jutanugarn holds a three-stroke lead over World No. 1 Lydia Ko midway through the second round of stroke-play qualifying at the 6,291-yard, par-72 Lake Merced Golf Club.

Jutanugarn assembled two steady rounds of 71 featuring four birdies and three bogeys each to easily earn one of the 64 available spots for Wednesday’s opening match-play round. However, the 16-year-old from Thailand did point to some faults in her game.

“It wasn’t easy,” said Jutanugarn, the 2012 Women’s Western Amateur champion. “My driver was not very good today, but my putter was better. I made long putts two times and some short putts two or three times.”

Jutanugarn also earned medalist honors at the 2011 Girls’ Junior conducted at Olympic Fields C.C. outside Chicago, a fact that she takes with a grain of salt.

“Being medalist is good, but in match play, it’s nothing,” said Jutanugarn. “I just do my best, and everybody’s the same. Everybody’s tired at the first hole.”

Ko, who currently sits atop the Women’s World Amateur Golf Ranking and was low amateur at the U.S. Women’s Open nine days ago, had her hands full early, opening with double bogey-bogey on the inward nine. However, a 30-foot birdie putt at the par-3 12th, her first of the championship, came at just the right time.

“The first couple of holes, my drives were going everywhere,” said Ko, who won the 2012 New South Wales Open, a professional event, earlier this year as well as the Australian Amateur. “But then on 12 I had my first birdie of the tournament and on 13 I had a good drive down there, so I think I got my confidence back.

“I think my putting got better then and the confidence started to rise because I was putting good at the [U.S. Women’s] Open and I was kind of shocked after yesterday.”

Mexico’s Marijosse Navarro, who won her home country’s 2012 Women’s Amateur, and local favorite Casie Cathrea, of Livermore, Calif., recorded holes-in-one on the third hole, which played to 122 yards on Tuesday. Cathrea, who has committed to attend Oklahoma State University in the fall of 2013, carded a 6-under 66, the championship’s lowest 18-hole score so far.

Canadian Brogan McKinnon, who was one shot behind Jutanugarn after Monday’s first round, carded a 4-over 76 to finish at 4-over 148, but will easily make match play.

Karen Chung, the 2008 runner-up from Livingston, N.J., sits at 8-over 152, while 2010 runner-up Katelyn Dambaugh, of Goose Creek, S.C., returned an 11-over 155.

Tuesday brought polar-opposite weather conditions from Monday, with sunny skies, relatively calm winds and temperatures in the low 60s.

Seventy-seven players have taken to the course for the afternoon wave, including Kathleen Gallagher, who was two strokes off the lead following Monday’s round of 73.

If necessary, a playoff for the final berths in the 64-player match-play bracket will be conducted immediately following play.

The U.S. Girls’ Junior continues Wednesday with the first round of match play. The second and third rounds will be played Thursday, and the quarterfinal and semifinal matches are on Friday. The 36-hole championship final will be played Saturday.

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

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