In-form Ratchanok Intanon beat Wang Yihan of China 21-11, 21-19 on Saturday to move to the final of the Superseries Premier Malaysia Open badminton tournament.
The straight-sets victory by the fourth-seeded Thai star was the first over her Chinese in 13 attempts.
The 21-year-old former world champion used her power to easily win the first set and showed her poise by winning six consecutive points to wrap up the match in the second set after Wang had built a 19-15 lead.
Ratchanok will meet Taiwanese Tai Tzu-ying, who defeated Saina Nehwal of India 21-19 and 21-13. The decider in the $500,000 tournament will take place on Sunday in Shah Alam, Malaysia.
Ratchanok went to Malaysia full of confidence after winning the India Open last week. The victory in India followed a win at the Thailand Masters in February, which signalled an end to a run of poor results. She is also on course to qualify for the Rio Olympics.