Teenage qualifier Linda Noskova is through to the Adelaide International final after pulling off a shock victory over injured top seed Ons Jabeur.
Jabeur needed a medical timeout for treatment on her back during the opening set and the world No.2 looked restricted at times on the way to a 6-3 1-6 6-3 defeat.
Noskova, an 18-year-old Czech ranked 102, will take on world No.5 Aryna Sabalenka in Sunday's final.
Sabalenka booked her spot with a 6-3 6-2 win over Irina-Camelia Begu.
Noskova has now won six consecutive matches in only her sixth appearance in the main draw of a WTA event.
She had to save match points during qualifying just to make it to the main draw of the Adelaide International and she is now just one win away from snaring a dream WTA title.
Noskova was trying her best to stay level-headed after posting the biggest win of her career with victory over Jabeur.
"Definitely a tough match. I don't think either of us played 100 per cent," Noskova said during her on-court interview.
"So I'm glad I had the last point to win. I'm just really glad to play like this.
"I'm just going for it 100 per cent all the time. It's just in or out. I'm just trying to push through."
Jabeur only got 50 per cent of her first serves in, and converted just two of her 12 break-point opportunities.
Her 33 unforced errors also played a key role in the loss.
Earlier in the day, Sabalenka made five double-faults but finished the match with her sixth ace as she booked her spot in the decider.
Sabalenka won more than 80 per cent of points on her first serve and controlled the contest from the baseline, proving far too powerful on the ground.
"I'm happy with the level I played," Sabalenka said, having advanced to the final without dropping a set.
"She's playing a little bit different style, so I'm super happy that I was able to win this match."
Sabalenka is chasing her first WTA title since beating Ash Barty on clay in Madrid in May 2021.
The 24-year-old lost three finals last year, including to Carolina Garcia at the elite season-ending WTA Finals in Texas in November.
Sunday's final will be Sabalenka's first singles title decider in Australia.
It is the second time in three years she's made the final at her first event of the season, after winning Abu Dhabi in 2021.
"It's going to be a great battle, so I'm really looking forward to this final," Sabalenka said.
"Probably we did everything right in the pre-season. I think this is the key.".
Sabalenka spent a month in Dubai preparing for her 2023 campaign, during which she hopes to break through at grand slam level.
The Belarusian reached semi-finals at Wimbledon (2021) and the US Open (2021, 2022).