Yang missed a 6-foot birdie try before Tseng holed the winning putt on the par-5 18th.

Both players closed with 3-under 68s to finish at 12-under 201 on the Pinnacle Country Club course.
Yang parred the final 11 holes of regulation, holing a 4½-foot putt on the 18th to force the playoff.

Tseng bogeyed the par-4 13th to drop to 10 under, then rallied with birdies on the par-5 14th and par-4 16th  holing an 8-foot putt to tie Yang.

On the 18th in regulation, Yang aggressively went for green in two shots, but hit her approach shot way left of the greenside grandstands before chipping on and saving par. Tseng reached the green in three shots and had a chance to win, but missed a 4-foot birdie putt.

The 22-year-old Tseng leads the tour with five victories this season, including major wins in the LPGA Championship and Women's British Open, and also has won three other events this year. She also succesfully defended her title in the Women's British Open.

Ai Miyazato was third at 11 under. Cristie Kerr was another stroke back.

Sandra Gal had the best round of the day, a 64 that left her tied for fifth with Amy Hung  and Belen Mozo at 9 under. The German star had nine birdies, including five in her first nine holes, and two bogeys.

Paula Creamer, the world's No. 9 player, had a 69 to eighth with hometown favorite Stacy Lewis at 8 under. Creamer had five birdies in her first nine holes and was a stroke behind Yang through 10 holes, but dropped back with a bogey on the par-4 12th. After Creamer three-putted from 10 feet, she tossed her ball in a pond in frustration.