Chien will play against his fellowman Bao Phuong Vinh, marking the third time in 95 years of the championship where the final is between two players from the same country. Two Argentine players did so in 1938 and two Belgium players in 2017.
As Chien secured a 50-47 victory against Tasdemir in the semifinal, Vinh beat South Korean Cho Myung-woo, who won his first World Cup last year, by 50-48.
Chien and Vinh beame the second and third Vietnamese to enter the World Three-Cushion Championship, after Nguyen Duc Anh Chien, who lost to Tobjorn Blomdahl in the 2019 final.
The final will take place on Sunday night.