Alison Lee on Verge of Elusive Girls' Junior Title July 19, 2012 | Daly City, Calif. By David Shefter, USGA

Alison Lee had all facets of her game working in Friday's quarterfinal win over good friend Lauren Diaz-Yi. (Steve Gibbons/USGA)

There was an extra-long congratulatory hug on Lake Merced Golf Club’s 14th green Friday morning between Southern Californians Alison Lee and Lauren Diaz-Yi.

It was almost a bittersweet exchange. The two high school seniors grew up playing with and against each other. Neither one wanted to play each other. But as the match-play draw played out at the 64th U.S. Girls’ Junior, the two wound up pitted against each other in the quarterfinals.

In fact, Lee, 17, of Valencia, gave Diaz-Yi, 17, of Thousand Oaks, a hug late Friday after the two had won their third-round matches.

"I’m really bummed that she had to … " said Lee, the words trailing off. "I know I would be sad if she lost and she would be sad if I lost."

Unfortunately, every match has a winner and loser. And on this overcast morning, it was Lee and her impeccable all-around game that prevailed, 5 and 4.

Lee didn’t have long to get over the emotional victory. Forty-five minutes later she was on the first tee against World No. 1 Lydia Ko, of New Zealand. Ko dismantled Yueer Cindy Feng, 8 and 6, and has played just 53 holes in winning four matches.

"I’m excited to play with her," said Lee, who met Ko and her mother at the U.S. Women’s Open two weeks ago at Blackwolf Run in Kohler, Wis. "It’s a test for myself as well."

Lee certainly has been no slouch in match play, either. It’s just she’s gone virtually unrecognized this week, despite being an American Junior Golf Association All-American and a six-time Girls’ Junior participant. Like Ko, she also made the 36-hole cut at the Women’s Open, the second time she has achieved that feat. She also played 72 holes at the 2009 Women’s Open at Saucon Valley Country Club in Bethlehem, Pa., carding a final-round 70.

But this week, attention has mainly gone to Ko or defending champion/medalist Ariya Jutanugarn, the world’s No. 2- ranked player. In fact, of the four remaining players, Lee is the only one not ranked among top 10. Australia’s Minjee Lee is World No. 8.

That doesn’t bother Lee. She’s happy to let her play do her talking, and it’s been consistent since she struggled to an opening-round 78 on Monday in the stroke-play portion of the championship. Lee even defeated Australia’s Su-Hyun Oh, ranked 23rd in the world, in the second round, 5 and 4.

Against Diaz-Yi, Lee didn’t make a bogey and outside of pulling a birdie putt that would have closed the match at the 13th hole, was solid on the greens. She made a brilliant par save at the fourth, chipping from 75 yards to 6 feet to halve the hole. She knocked a wedge to 4 feet at the par-5 ninth for a winning birdie. At Nos. 11 and 12, she needed to hole 4- and 5-footers for par to halve.

"Overall, I played great today," said Lee, who has committed to play for UCLA in the fall of 2013. "I am happy with my results. I didn’t make too many mistakes."

That wasn’t the case for Diaz-Yi, a Virginia commitment for 2013. She pull-hooked her opening tee shot and bogeyed the hole. From there on out, her drives were solid – and often past Lee’s – but she never got dialed in with some of her approach shots. She missed the green short with her tee shot at the 122-yard third hole and also came up short at the fourth after a long drive. Then at No. 11, she air-mailed the green with a wedge in her hand while trying to play a knock-down shot.

"The short-game part of my game was not the base," said Diaz-Yi, competing in her first U.S. Girls’ Junior. "My putting was absolutely horrible. Me and my caddie had trouble reading the greens today."

If anyone could relate to having a bad day, it’s Lee. A year ago, she struggled mightily with her game. She badly missed the match-play cut at the U.S. Women’s Amateur. Two years ago at the Girls’ Junior, she also failed to make match play, despite entering the competition as one of the pre-championship favorites. Last year at Olympia Fields, outside Chicago, she advanced to the third round before losing to fellow Southern Californian Amy Lee (no relation).

But in 2012, things seem to be headed back in the right direction. She won the ANNIKA Invitational earlier this year, then qualified for the Kraft Nabisco Championship in March at a special Junior Challenge held at Mission Hills C.C. in Rancho Mirage, Calif.

At Women’s Open sectional qualifying at nearby Half Moon Bay, she was the first alternate, but got into the field a week before the competition started in Wisconsin. Lee then made the cut, one of three amateurs out of 28 who started to do so.

Now she is two wins away from landing the biggest prize in girls’ golf.

"I didn’t have trust in myself and my game," said Lee of her struggles. "In the long run, I realized it’s all in my head. I have all these skills inside me and I have played well before. I realized golf is like 90 percent a mental game. I need to play fearless golf and try not to hesitate or anything."

It’s that kind of attitude that Lee will need to beat Ko in the semifinals. She knows that too.

"This is my sixth time, so this is literally my last chance to win this tournament," said Lee. "It would mean a lot."

David Shefter is a USGA senior staff writer. Email him at dshefter@usga.org.