Defending champion Eun Jeong Seong of South Korea won her opening match Wednesday in the U.S. Girls' Junior Championship, topping Katherine Muzi of Walnut, California, 5 and 4.

"I didn't have a birdie today," the 16-year-old Seong said. "But she made a couple mistakes today, which is how I won."

Seong will face Taiwan's Yu Chiang Hou, a 3-and-2 winner over Elizabeth Wang of San Marino, California, in the second round at Ridgewood Country Club.

Co-qualifying medalist Hye-Jin Choi of South Korea topped Nicole Whiston of San Diego 4 and 3.

"I think everything worked out well today," said Choi, also 16. "My putts were great and my drivers were great. I started out really great, which took some pressure off me and allowed me to play well."

Kendall Griffin of Sebring, Florida, edged co-medalist Sadie Englemann of Austin, Texas, 1 up.

"I thought I played really well, but she made a lot of putts," the 14-year-old Englemann said. "She played really awesome, I didn't make too many, but I thought I played well."