Chang Kai-chen of Taiwan beat top-seeded Sam Stosur of Australia 6-4, 4-6, 7-6 (3) on Saturday to advance to the final of the Japan Open.
The 134th-ranked Chang broke Stosur twice in the opening set. She eliminated three seeded players on the way to her first career WTA Tour final.
The 21-year-old Chang will face Britain's Heather Watson on Sunday after she defeated local favorite Misaki Doi of Japan 7-6 (2), 7-5 in the other semifinal.
Watson broke Doi four times in the second set to make up for losing her own serve three times. The 20-year-old Watson also will be appearing in her first career WTA final — just three weeks after Laura Robson became the first British woman in 22 years to reach a title match.