Ai Miyazato shot a 7-under 65 on Saturday to take a one-stroke lead over top-ranked Yani Tseng after the third round of the LPGA Thailand.
Miyazato, the Japanese player who won the 2010 tournament, birdied five of the first six holes on the back nine. She had a 14-under 202 total on Siam Country Club's Pattaya Old Course.
Tseng, the winner last year, shot her second straight 65 after opening with a 73. The Taiwanese star had 12 worldwide victories last year, seven on the LPGA Tour.
Australia's Karrie Webb and South Korea's Jiyai Shin were 12 under.
Webb shot a 71, and Shin had a 68.