Published: Jul 23, 2011 1:28 AM EDT
Updated: Jul 23, 2011 6:30 AM EDT

OLYMPIA FIELDS, Illinois (AP) - Thailand's Ariya Jutanugarn advanced to the finals of the U.S. Girls' Junior Championship with an 8 and 6 victory over 20th-seeded Amy Lee of the United States on Friday.

Ariya, the top-ranked player in the field, won five holes on the front nine, then closed Lee out by taking the 10th, 11th and 12th holes. She was 5-under-par for her abbreviated round.

The Bangkok native will face Dottie Ardina of the Philippines, who beat seventh-seeded Yu Liu of China 2 and 1.

Ardina was 1 down to Liu after a bogey on the par-4 13th hole, but won the par-3 14th with a par, and then won the 16th and 17th with par 4s to win a spot in the final.

"If I win, it's a big win for me, for my lifetime," Ardina said. "I have to make my birdie putts. I missed a lot of them today."

Earlier in the day, Ariya scored a 1 up victory over Gabriella Then in the quarterfinals, and Lee beat Talia Campbell 1 up. Ardina beat Summar Roachell 5 and 4 in the thunderstorm-interrupted match, and Liu beat Karen Chung 6 and 5 in her morning match.