SAN MARTIN, Calif. -- Lydia Ko already has 13 career victories on the LPGA Tour, including two major championships, and is ranked No. 1 in the world at the age of 19.
On Sunday, the teen-ager from New Zealand will have a chance to add a U.S. Women's Open title to her already impressive resume.
Ko moved to the top of the leaderboard on Saturday by shooting a 2-under 70 with a birdie on the final hole in the third round to take a one-shot lead at CordeValle Golf Club.
Ko is at 7-under 209 for the tournament, one shot ahead of Eun-Hee Ji and second-round leader Sung Hyun Park, both of South Korea, entering the final round. Ji also carded a 70 and Park struggled to a 74.
Ko hasn't finished higher than a tie for 12th in four previous tries at the U.S. Women's Open.
"I think I've always come off after a U.S. Open and said, 'Hey, I could have done a little better,'" Ko said. "I always felt like something was missing.
"But I'm happy with the way I've kind of progressed playing these U.S. Open championships. The most memorable of them all is Blackwolf Run when I first played (in 2012), because I was so nervous. I couldn't control it at all.
"It just shows how much this championship means to me and means to the women's game, and how important it is for any player and what a big honor it is to be holding the trophy at the end of Sunday."
Ko sank a nine-foot birdie putt on the par-5 18th hole to break a three-way tie for first with Ji and Park.
Ko came from behind this year to win ANA Inspiration and last year to win the Evian Championship, her two major titles. She had the 54-lead earlier this year at the Women's PGA Championship but lost to Brooke Henderson in a playoff.
"I'll take any shot advantage I can, because there is still a lot of golf to be played," Ko said. "You just never know."
Ji is the only player at or near the top of the leaderboard who has won the U.S. Women's Open, capturing the title in 2009. That year she was in second place after three rounds.
Ji has no other finish in the tournament higher than a tie for 27th in eight attempts. She has only one other victory on the LPGA Tour in 10 seasons.
"I forget it," Ji said of her 2009 title. "I just play, focus on my game and try to play my game and be patient out there."
Yang had at least a share of the 54-hole lead in each of the last two U.S. Women's Opens. She finished runner-up to In Gee Chun of South Korea last year and finished fourth in 2014 when Michelle Wie won.
This time she will try to come from behind to win after shooting 73 in the third round.
"It's so windy out there, it wasn't easy," said Yang, who has four top-5 finishes in the past six years at the tournament. "I had to save pars, up-and-downs quite a lot, but I saved it. I'm still hitting it good. So I'm looking forward to it."
Park was 8-under after the second round and led Yang and first-round leader Mirim Lee of South Korea by two shots, and Ko and Haru Nomura of Japan by three.
Park was 9-under for the tournament through eight holes Saturday, but double-bogeyed the ninth, falling into a tie for first with Yang. Park shot 37 on the back nine to stay in contention.
"I have done my best today," said Park, who's playing in her first U.S. Women's Open. "There's still one more round going on, and it's great that I had this experience to come out here to the U.S. Open."
Lang made a strong move up the leaderboard, with her 68 the best score of the day. She jumped from a tie for 20th to a tie for fourth.
Lang has one career LPGA Tour victory but four top-15 finishes in the U.S. Women's Open. She tied for second in 2005, fifth in 2010, seventh in 2013 and 14th in 2015.
"I thought I was going to shoot 5- or 6-under," Lang said. "I really felt good about it. I thought (9 a.m.) was such a good [tee] time. The greens were going to be soft and some of the pins were accessible, and I was just playing really good. But I'm very happy with 4 under. I'm excited to be back in the mix for sure."
Stanford, who birdied three of her final four holes, moved from a tie for 10th to sixth place.
NOTES: Lee Lopez had a hole-in-one on the 201-yard, par-3 12th hole. She shot 71 and is six strokes back. ... Stacy Lewis, a two-time major champion, shot 69 and moved up 21 spots to a tie for eighth. ... Brooke Henderson, 18, of Canada, who won the Women's PGA Championship last month, stumbled to her second 76 of the tournament and was tied for 58th.