CANCUN, Mexico -- Jessica Pegula scored her third victory over a No.1 player this year with a definitive 6-4, 6-3 win against World No.1 Aryna Sabalenka on Tuesday at the GNP Seguros WTA Finals Cancun. The victory, combined with Elena Rybakina's win over Maria Sakkari, means Pegula will win the Bacalar Group and advance to Saturday's semifinals.

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After a 0-3 singles drought at last year's WTA Finals in Fort Worth, Pegula is the only undefeated player left in the Bacalar Group, while Sabalenka drops to 1-1. 

Earlier this year, Pegula defeated then-No.1 Iga Swiatek in Montreal and the United Cup in Sydney.

For Sabalenka, the battle with Swiatek for the year-end top ranking intensifies.

Pegula said she’s a different player than the one who qualified for the WTA Finals for the first time in Fort Worth.

“I feel more comfortable playing [top players] this year, I feel more confident,” she told reporters afterward. “I don’t think it feels like such a big deal. Last year when I made Top 5, I think I psyched myself out a little bit -- not a lot. You have a couple thoughts in your head -- do I really belong at that level?

“I was always good at beating those below me, but now you have to beat the one or two before you. I think you put a bigger emphasis on that. And I think this year, I’ve not really cared. I’ve had more confidence in those matches and that’s why I’ve got more top wins -- in big moments. I feel that’s where I’ve improved a little bit.”

It was another breakthrough for the 29-year-old American. She had lost four of her previous five matches against Sabalenka. Pegula is now 49-0 this year after winning the first set and an impressive 7-4 against opponents in the Top 10. Pegula is the first American to produce five straight Top 10 wins since Sloane Stephens in 2018.

Sabalenka scrambled to save two break points in her opening service game, but at 2-all, Pegula broke through. Two double faults put Sabalenka in a love-40 hold and a wide forehand gave Pegula her first substantial lead.

With Sabalenka serving at 2-4, it happened again when she lashed a backhand wide. Serving for the set a second time, Pegula closed it out with a terrific backhand that Sabalenka was unable to dig out.

Hawk-Eye

Pegula generated 14 break points in the match and broke serve five times. She did it by holding firm to an aggressive return position and landing 86% of her first-serve returns. Sabalenka lost her first two service games of the second set and ultimately trailed 4-0 before holding serve twice.

With Pegula serving at 5-3, she crafted two match points -- but lost them both, one on a double fault. Subsequently, Sabalenka lost her first three service points, but saved four more match points before Pegula closed it out.

“No matter who it is, we all get into the position like I did today, where you save match points and you feel you can win or you’re fighting to stop the momentum and close out the match,” Pegula said. “You don’t learn that until you go through it several times and experience it.

“I try to use my match experience as best I can. The more you put yourself in those situations, the better you feel when they come up again -- it doesn’t feel as if you have to panic as much.”

Sabalenka sabotaged herself with 33 unforced errors and only 15 winners. Pegula was a typically tidy 12 and 17.

“I guess she just played great tennis,” Sabalenka said. “Yes, I could come back in this match -- but it was too much.

“But, I still get a chance to pass the group, so I’m trying to stay strong.”