The top two seeds in the women's draw were knocked out of the Badminton World Federation (BWF) Indonesia Open at the semi-final stage in Jakarta.
India's Pusarla Venkarta Sindhu reached her first final of 2019 at the Super 1000 World Tour event at Istora Gelora Bung Karno by defeating second seed Chen Yu Fei of China 21-19, 21-11.
"Ups and downs are always there," said Sindhu after the match.
"I have learned from my mistakes and have come back much stronger.
“It is the first final this year so I hope I don’t miss out on the opportunity to get the gold.
"There’s only one year until the Olympics so every tournament is equally important but for me, it’s just about taking it step by step."
Sindhu will face long-time rival Akane Yamaguchi in the final after she defeated top seed Tai Tzu-ying from Chinese Taipei 21-9, 21-15.
The Japanese fourth seed was in command from the off and goes into tomorrow's final as the favourite owing to her 10-4 head-to-head record against Sindhu.
In the men's semi-finals, Kantaphon Wangcharoen's stunning week in Jakarta came to an end as he succumbed to fourth seed Chou Tien-chen.
The Thailand player had fought back to level at 1-1 before Chinese Taipei's Chou made his past experience count in a 21-19, 18-21, 21-16 triumph.
Chou will face Denmark's Anders Antonsen in the final after he defeated Hong Kong's Wong Wing Ki 21-17, 21-10.
An all-Indonesian men's doubles final beckons tomorrow after the hosts enjoyed victory in both semi-finals.
Marcus Fernaldi Gideon and Kevin Sanjaya Sukamuljo were electric on court as they destroyed Li Jun Hui and Liu Yuchen 21-9 21-13.
They will take on compatriots Mohammad Ahsan and Hendra Setiawan after they won in three sets.
The fourth seeds ousted Japanese pair Takuro Hoki and Yugo Kobayashi 17-21, 21-19, 21-17.