Women's top seed Ons Jabeur went 3-0 behind in the first set against Ukrainian Marta Kostyuk, but rallied to win 7-6 (7/5), 7-5 at the Adelaide International on Friday, boosting her Australian Open preparations.
"I didn't start the way I wanted to ... I just kept telling myself to put two or three balls in to get in the game," said Jabeur.
"I'm pretty happy I didn't go three sets with her."
The Tunisian will take on rising Czech teen Linda Noskova for a place in the final after she outlasted veteran Victoria Azarenka 6-4, 6-7 (3/7), 7-6 (8/6).
World No 5 Aryna Sabalenka held off Marketa Vondrousova to book her place in the last four.
The Belarusian overcame hot conditions to dismiss her Czech opponent 6-3, 7-5 and continue her strong 2022 late-season form where she finished runner-up at the WTA Finals.
The second seed's reward is a last-four clash with Romanian veteran Irina-Camelia Begu, who upset Russian world No 9 Veronika Kudermetova 7-5, 6-4.
"It was a tough match and she fought until the end and I was really happy I was able to win this match," Sabalenka, who is yet to win a Grand Slam, said.
"I think because I'm staying really calm and I feel like I'm at home here, that's why I play really well. I haven't dropped a set yet. Hopefully, I'll keep going like that."
The Australian Open starts in less than two weeks.