Tseng won the LPGA HanaBank Championship in South Korea on Sunday. It marked her sixth LPGA-affiliated victory of the year. She also has wins on tours in her native Taiwan and Australia.
"I feel like my mental game is getting mature and my mental [game] is thinking more positive instead of negative," Tseng said after the win in South Korea.
"I feel like this year I can trust in myself more and believe in myself that I can do this and I can win in this tournament and it just feels so much different than the last three years."
Tseng has a rankings points average of 17.48, well ahead of second-ranked Suzann Pettersen (11.48) and No. 3 Cristie Kerr (11.30). Choi Na-yeon, who was a two-time defending champion in South Korean and finished second this year, is fourth at 9.44 with Jiyai Shin (8.63) in fifth.
Ahn Sun-ju is a close sixth with an average of 8.50 and Ai Miyazato (7.62) is ranked seventh.
Brittany Lincicome (7.47) used a final-round 66 to pull into a tie for third in South Korea. That lifts her ranking two places to No. 8. Paula Creamer (7.33) and Stacy Lewis (7.13) are each knocked down a spot to ninth and 10th, respectively.