The Chinese Taipei 21-year-old, who has rarely competed on the HSBC BWF World Tour, upset fifth seed Ng Ka Long Angus 21-11 21-15. Su had earlier beaten Parupalli Kashyap in the second round and Yeoh Seng Zoe in the quarterfinals.
Su takes on Indonesia’s Chico Aura Dwi Wardoyo, who made his first final since the DAIHATSU Indonesia Masters in January, as he overcame home hope Wang Tzu Wei 21-6 21-18. Wardoyo hadn’t crossed the second round of his last six events.
In women’s singles Beiwen Zhang earned a shot at her first title of the season as she made the final.
The world No.15 outplayed young Thai talent Pitchamon Opatniputh 21-18 21-15 to set up a title bout with home favourite Tai Tzu Ying.
Top seed Tai, who brushed aside Thailand’s Pornpicha Choeikeewong in 29 minutes, will be looking for her fifth title at her home event.
Malaysia are in contention in men’s doubles as well, with defending champions Man Wei Chong/Tee Kai Wun beating compatriots Ong Yew Sin/Teo Ee Yi, to make their second World Tour final this year after the PERODUA Malaysia Masters.