Sonay Kartal's dream comeback continued as she beat Jelena Ostapenko 7-6 (11-9), 7-6 (7-5) to advance to the biggest final of her career at the Wuhan Open.
Kartal hit back from behind in both sets and fought off a total of six set points to beat the former French Open champion in only her second tour-level tournament back after injury.
In Sunday's final, Kartal will play the winner of a Polish duel between former world number one Iga Swiatek and Maja Chwalinska.
The 24-year-old, who started this week ranked 170 due to her recent inactivity, becomes the lowest-ranked player to reach a WTA 1000 final since the format began in 2009.
Her result also means Kartal is guaranteed to jump into the world's top 50 in the new WTA rankings next week, overtaking Katie Boulter to become British number one.
Kartal said: "That was probably one of the toughest matches I've played in. I knew exactly how she was going to play.
"At times she's unplayable, and sometimes you have to ride that wave. Mentally I think this is one of the best performances I've had in my career."
Kartal clawed back a double break in the opening set and rode her luck on serve before forcing a marathon tie-break which she edged 11-9 after saving two set points.
And she also had to dig deep in the second set, recovering another break and saving two more set points on serve at 6-5 before forcing a second tie-break which she won to complete a famous win.
Her victory over Ostapenko extended a remarkable series of wins against 2021 Olympic champion Belinda Bencic, ex-Wimbledon finalist Jasmine Paolini, and world number six Elina Svitolina.
Kartal made her breakthrough by reaching the fourth round of last year's Wimbledon, but found her momentum stalled after sustaining a back injury that kept her out of action for six months.
She showed positive signs by winning two matches on her return at the China Open earlier this month, but scarcely could have expected such a level of success so soon.