French Open champion Mirra Andreeva stormed past Aryna Sabalenka 6-4, 6-0 to reach the last four of the WTA Finals on Wednesday as Elina Svitolina kept her bid on track with a three-set win over Karolina Muchova.
Russian 19-year-old Andreeva held her nerve after falling behind 4-1 in the opening set -- winning the last 11 games to seal the round-robin victory in just 62 minutes.
"Oh my God, I'm even happier than I was after my first match," Andreeva said. "I feel like I can play another two matches, I'm so full of energy. I'm so pumped up. I'm so happy."
Andreeva, whose three titles this year include her maiden major at Roland Garros, is making her singles debut in the elite season-ending event.
The world number three seemed to be feeling the nerves in the early going against second-ranked Sabalenka.
Irked that she had given up a break with a double fault, she was able to flip the switch, dealing handily with Sabalenka's big serves and pushing the Belarusian star back with her own big groundstrokes.
Andreeva crucially kept momentum on her side with a break for a 3-0 lead in the second set.
Sabalenka, trailing 0-40, saved three break points, but Andreeva gave herself another with a swinging volley winner and grabbed another break when a Sabalenka forehand flew just long.
The increasingly demoralized Sabalenka had no answer. After the Belarusian smacked a backhand into the net to give her opponent match point Andreeva polished things off with a service winner.
It was another disappointing performance for the 28-year-old Sabalenka, whose three wins this season include prestigious back-to-back victories at Indian Wells and Miami but no Grand Slams.
Making her sixth straight Finals appearance, Sabalenka can still advance if she beats Svitolina in their final round-robin match on Friday.
Svitolina roared back from a set down to beat Muchova 3-6, 6-2, 6-2.
Ukrainian veteran Svitolina lifted the WTA Finals trophy in 2018 but hadn't been back to the elite season-ending event since 2019.
She got off to a rocky start against Muchova, who broke Svitolina three times in the opening set.
Trailing 2-1 on serve in the second Svitolina found her range, winning five straight games to force a third set.
"I was not happy with the first set," Svitolina said. "I didn't play as well. I just made some adjustments, tactical adjustments.
"I think it helped me also to be more aggressive, because I was too passive in the first set," Svitolina said.
Muchova's second round-robin defeat coupled with Andreeva's victory means the Czech was eliminated from semi-final contention.