The 17-year-old third seed, who was forced the distance in her three earlier matches in the tournament, simply ran out of steam against an inspired Kaori Imabeppu, who only took 40 minutes to carve out an emphatic 21-15, 21-18 victory.
It was sweet revenge for Imabeppu, who was lost her only other encounter with Tzu Ying earlier this year at the Wilson Swiss Open Grand Prix Gold.
The unseeded Japanese shuttler will meet Singapore’s Fu Mingtian in Sunday’s final after the latter ousted South Korea’s Hwang Hye Youn in the other semi-final.
Fu Mingtian, like Imabeppu, had lost her only other match to Hye Youn, but that took place three years ago at the Aviva Singapore Open.
On Saturday, the Singaporean turned on the style to register a 21-19, 21-15 victory in 38 minutes to reach her first Grand Prix final of the year.
Meanwhile, top seed Nguyen Tien Minh of Vietnam, stayed on course to win his home title for the third time in four years when he reached the men’s singles title decider.
Tien Minh, who won the crown in 2008 and 2009, has been in commanding form since the start of the tournament and has yet to drop a game in the competition. On Saturday, he needed only 30 minutes to thrash India’s R. M. V. Gurusaidutt 21-5, 21-9.
Waiting for him in the final is Japan’s Sho Sasaki (picture). The second seed, who won titles in Australia and the United States this year, also overcame an Indian opponent in the semi-finals.
However, Sasaki had to overcome a fighting Ajay Jayaram before scoring a 12-21, 21-14, 21-16 victory in 52 minutes.
For full results, click here.