The 2022 Wimbledon champion will face the Czech Republic's Linda Noskova in the semi-finals at the Tokyo tournament after her victory on Friday.
The other semi will be between Swiss former Olympic champion Belinda Bencic and 2020 Australian Open winner Sofia Kenin.
The Kazakhstan star Rybakina moved ahead of Mirra Andreeva to take the eighth spot for November's lucrative WTA Finals in Saudi Arabia.
"It's great to qualify and play some more matches, especially against top players," Rybakina said.
"Last week, I was focusing one match at a time and I knew that to qualify it's going to take a long road."
At the WTA Finals, scheduled for November 1-8, Rybakina will join top-ranked Aryna Sabalenka, Iga Swiatek, Coco Gauff, Amanda Anisimova, Madison Keys, Jessica Pegula, and Jasmine Paolini.
Gauff will be the defending champion in Riyadh. The American beat China's Olympic champion Zheng Qinwen in last year's final and received $US4.8 million ($A7.4 million) in prize money.
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