Mirra Andreeva beat Aryna Sabalenka on Wednesday at the WTA Finals in Indian Wells. She won 6-4, 6-0 and locked up a spot in the semifinals.

She did it the hard way. Andreeva trailed 4 - 1 in the first set. Then she won 11 games in a row and never let Sabalenka back in.

This was a big win. Sabalenka is ranked No. 2 in the world and owns four major titles. Andreeva, ranked No. 3, has now won both of her Group 2 matches, which makes her the group winner.

It is also her first time at the WTA Finals. Only the top eight players of the year get an invite to the last big event of the season.

Andreeva is 19 and from Russia. She won her first Grand Slam title at the French Open this year. Her coach is Conchita Martinez, a former Wimbledon champion.

Andreeva has been open about how much she hates to lose. After falling in the Madrid Open final this spring, she said every loss feels like the end of the world to her. That fire was easy to see against Sabalenka once the comeback started.

Sabalenka is not out yet. She can still reach the semifinals by beating Elina Svitolina on Friday, with the last spot from Group 2 on the line.

Read more about the other matches here.

What's next: Andreeva closes group play against Karolína Muchova on Friday. The WTA Finals semifinals are Saturday, November 14, and the final is Sunday, November 15, at the Indian Wells Tennis Garden, a few hours' drive from San Diego.