Samantha Stosur ousted in semis
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.
Need the scores from any match played in today's tournaments? Results
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.
Copyright 2012 by The Associated Press
MORE TENNIS HEADLINES
- Serena rolls at Stanford in first match back
- Nadal (wrist) pulls out of two Open tuneups
- Lisicki sets WTA record with 131 mph serve
- Baghdatis gets Open spot after Haas bows out