The 17-year-old French Open semi-finalist, who had stunned five-times grand slam champion Iga Swiatek in the quarters and former Wimbledon winner Marketa Vondrousova in the round of 32, is the youngest player to reach a WTA 1000 Final.
Andreeva also becomes the youngest player to beat three grand slam winners at a single event since compatriot Maria Sharapova in 2004.
She's also only the third teenager to reach a final at one of the WTA's biggest events since they were introduced in 2009, following in the footsteps of grand slam champions Swiatek and Coco Gauff.
Wimbledon 2022 champion Rybakina, ranked seventh in the world, let a slender 2-1 lead slip in a tight opening set as momentum swung back and forth before Andreeva came out on top in Friday's clash.
But Rybakina forced a decider following a close second set where she had built a 4-3 lead and just as she looked to run away with the win after racing to a 3-1 lead in the final set, Andreeva roared back to win five successive games.
With the victory, world No.14 Andreeva also avenged her 2023 Beijing round-of-16 defeat against Rybakina.
"Last time we played it was a really tough match. She went for her shots and killed me in the end. This time I knew she'd hit hard. I tried to fight for every point and kept believing," Andreeva said.
Up next for Andreeva in the final is Denmark's Clara Tauson, who caused her own sensation by knocking out Aryna Sabalenka earlier in the tournament.
The 22-year-old world No.38 Tauson continued her brilliant run, reaching her first WTA 1000 final by beating Czech 14th seed Karolina Muchova 6-4 6-7 (4-7) 6-3 in the second semi-final.
