Mirra Andreeva was down 4-1 to the world No. 2. She did not lose another game.

The 19-year-old won the final 11 games to beat Aryna Sabalenka 6-4, 6-0 at the WTA Finals in Indian Wells on Wednesday. The match took 62 minutes.

The win puts Andreeva in her first WTA Finals semifinal as the winner of her group.

A stunning turnaround

Andreeva won 45 of the last 55 points. The only scare came when she trailed 15-30 while serving for the first set. She answered with three straight aces.

She hit 16 winners with just six unforced errors. Sabalenka had 23 unforced errors and no aces.

"I will be honest, I feel like Aryna did not have the best day," Andreeva said after the match. "I'm just happy. I had a goal in front of me to commit no matter what and control the things I can control."

Making history

Andreeva is the youngest player to reach the WTA Finals semifinals since Caroline Wozniacki in 2009. She is the fifth teenager to do it since the round-robin format began in 2003, joining Maria Sharapova, Ana Ivanovic, Wozniacki and Coco Gauff.

She also beat Elina Svitolina 6-4, 6-0 in her opening match. That makes her the first player in tournament history to win a 6-0 set in each of her first two WTA Finals matches.

What's next

Sabalenka, who won the Indian Wells title earlier this year, will play Svitolina on Friday with the last semifinal spot from the group on the line. Svitolina beat Karolina Muchova 3-6, 6-2, 6-2 earlier on Wednesday.