DALY CITY, Calif. (July 19, 2012) -- The world’s top two ranked female amateurs remained on a collision course to meet in the championship match of the 64th U.S. Girls’ Junior.

Defending champion and medalist Ariya Jutanugarn, 16, of Thailand, ranked second in the Women’s World Amateur Golf Ranking, and top-ranked Lydia Ko, 15, of New Zealand, each won a pair of matches Thursday at the 6,291-yard, par-72 Lake Merced Golf Club to reach the quarterfinals.

Jutanugarn had the easiest route, defeating 2010 runner-up Katelyn Dambaugh, of Goose Creek, S.C., 5 and 4, before blitzing last month’s U.S. Women’s Amateur Public Links runner-up Ashlan Ramsey, of Milledgeville, Ga., 8 and 6. Ko defeated Hee Wook Choi, of San Diego, 7 and 6, before edging past Nicole Morales, of South Salem, N.Y., 2 and 1, in the third round.

The other six golfers to reach the quarterfinals are Minjee Lee, of Australia; Casie Cathrea, of Livermore, Calif.; Chinese-born Yueer “Cindy” Feng, of Orlando, Fla.; Kelli Murphy, of Elgin, S.C.; Alison Lee, of Valencia, Calif.; and Lauren Diaz-Yi, of Thousand Oaks, Calif.

With Thai friend Sagee Palavivatana on the bag, Jutanugarn posted six birdies and an eagle in her afternoon third-round win over Ramsey. Ramsey had gone 20 holes in the morning to beat 2011 semifinalist Amy Lee, of Brea, Calif.

“I played really good today,” said Jutanugarn, winner of this year’s Women’s Western Amateur. “I was very confident with my game today because I hit my driver good and hit my iron shots good, and my putter was very good today.

“The tournament is not done, so everybody [still left] has a chance to win. So I have to keep it up.”

Said Ramsey: “It’s pretty difficult to beat someone who is playing that well. But I don’t think anyone could have beaten her today.”

Next up for Jutanugarn will be Cathrea, a local favorite from across the Bay. Cathrea ousted 2008 runner-up Karen Chung, of Livingston, N.J., 2 and 1, in the morning, then cruised by Anne Freman, of Las Vegas, 6 and 4. Cathrea seems to have found her game after opening stroke-play qualifying with an 82. She bounced back with a championship-best 66 on Tuesday and has been under par in her first three matches.

She closed out Freman with a conceded eagle-3 at the par-5 14th hole.

But Cathrea knows she can’t afford any mistakes in the quarterfinals Friday morning against Jutanugarn.

“I don’t think I am going to be relaxed at all,” said Cathrea, who will attend Oklahoma State in the fall of 2013. “I think honestly it will take a lot of pars and birdies, and a couple of eagles [to win]. We will see what tomorrow brings.”

The match of the third round belonged to Ko and Morales. They combined for 10 birdies – Ko recording six – and halved two holes with birdie, including the 17th, where the match ended. Morales rolled in a downhill 20-footer before Ko finished the win with a 4-footer.

“Nicole, she was kind of like a dog on your pants and wouldn’t let you go,” said Ko, the low amateur at the recent U.S. Women’s Open and the 2012 Australian Amateur champion. “I played Kim Williams from South Africa and she is kind of like that. She is really tough. I think Nicole is my toughest opponent after her. We both played really well.”

The match was tight throughout, although Morales missed a golden chance to square it at the par-5 ninth when she missed a 7-foot birdie attempt. “That was stupid right there,” she said.

Ko went 2 up at No. 11 when Morales bogeyed. It could have been 3 up had Morales not made an up-and-down par from a greenside bunker at the par-3 12th. Both players birdied the par-5 14 th hole and Ko made her lone mistake at the par-3 15th with a bogey to lose the hole. Ko regained a 2-up advantage with a birdie at 16.

“I was expecting her to be like any typical amazing golfer … and that’s what I got,” said Morales.

Ko, the youngest winner of a professional event (2012 New South Wales Open at 14) is now two victories away from the championship match.

“It’s getting closer and closer,” said Ko, “and my matches are getting tougher and tougher.”

The quarterfinals and semifinals are scheduled for Friday, with the 36-hole final on Saturday.

The U.S. Girls’ Junior is one of 13 national championships conducted annually by the USGA, 10 of which are strictly for amateurs.

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