INDIAN WELLS, California, Nov 13 - Mirra Andreeva said she has learned to recover more quickly from setbacks after the Russian teenager completed an unbeaten run through the WTA Finals round-robin stage on Friday.

Andreeva won her third group-stage match in straight sets after a late opponent change, having already secured a semi-final berth. The 19-year-old said the match against tournament alternate Diana Shnaider presented a new mental challenge because her progression was guaranteed, but she still wanted to preserve her momentum.

"Before the tournament started I was afraid that I wouldn't win a match in the group," Andreeva told reporters. "Now you see how it turned out."

The victory set up a first career meeting with American Jessica Pegula on Saturday. Andreeva described Pegula as one of the calmest players on tour and said coach Conchita Martinez would help prepare a detailed tactical plan.

Andreeva's poise in the desert marked a contrast with her emotional exit from Indian Wells in March, when she lost her title defence to Katerina Siniakova. Frustrated by the defeat, Andreeva launched into a profanity-laced tirade toward spectators and was booed as she left the court.

The French Open champion said her response to losses has changed significantly over the course of the season.

"Before it was super bad. I was very dramatic," Andreeva said. "It would take me a good two, three days. I wouldn't talk to anybody. I would just sit in the room locked up, not wanting to practice."

Now, she said, disappointment generally lasts a day at most before the demands of the tour force her attention back to training or the next match.

Andreeva said the Indian Wells setback came while she was trying to incorporate changes made in practice into her match play, which produced inconsistency and frustration. She said continued work on court, along with sessions with psychologists, helped her make progress.

The results have followed. Andreeva won her first Grand Slam title at Roland Garros this year and arrived at the WTA Finals for her singles debut after a 50-win season. REUTERS