NEW YORK >> Jessica Pegula shrugged off a sluggish start and came back from a set and a break down at the U.S. Open to defeat Karolina Muchova 1-6, 6-4, 6-2 on Thursday night for a berth in her first Grand Slam final.

The No. 6-seeded Pegula, a 30-year-old from New York, has won 15 of her past 16 matches and will meet No. 2 Aryna Sabalenka for the title on Saturday.

Sabalenka, last year’s runner-up to Coco Gauff at Flushing Meadows, returned to the championship match by holding off a late push to beat No. 13 Emma Navarro of the U.S. 6-3, 7-6 (2).

Things did not look promising for Pegula early: Muchova, the 2023 French Open runner-up but unseeded after missing about 10 months because of wrist surgery, employed every ounce of her versatility and creativity, the traits that make her so hard to deal with on any surface.

The slices. The touch at the net. The serve-and-volleying. Ten of the match’s first 12 winners came off her racket. The first set lasted 28 minutes, and Muchova won 30 of its 44 points.

Muchova grabbed eight of the first nine games and was one point from leading 3-0 in the second set. But she couldn’t convert a break chance there, flubbing a forehand volley, and everything changed.

Quickly, the 52nd-ranked Muchova went from not being able to miss a shot to not being able to make one. And Pegula turned it on, demonstrating the confident brand of tennis she used to eliminate No. 1 Iga Swiatek, a five-time major champion, in straight sets on Wednesday. Pegula had been 0-6 in major quarterfinals before that breakthrough.

Took Pegula a while to play that well Thursday, but once she got going, whoa, did she ever. All told, she collected nine of 11 games, a span that allowed her to not merely flip the second set but race to a 3-0 edge in the third.

For Sabalenka, when things suddenly got quite tight in the second set of her semifinal, and the Arthur Ashe Stadium spectators suddenly got quite loud while pulling for her American opponent, the 2023 runner-up found herself flashing back to a year ago at the same site.

“Last year, it was a very tough experience. Very tough lesson. Today in the match, I was, like, ‘No, no, no, Aryna. It’s not going to happen again. You have to control your emotions. You have to focus on yourself,’” Sabalenka said. “There was people supporting for me; I was trying to focus on them. I’m thinking, ‘Come on. There’s so many people supporting you. There is your team in the box. There is your family. Just focus on yourself and try to — not try, just fight for it.’”

Sabalenka moved into her second consecutive final at Flushing Meadows with a strong start and a late surge, taking the last seven points to beat Navarro with her usual brand of high-risk, high-reward tennis.

Sabalenka, a 26-year-old from Belarus, has won each of the past two Australian Opens but ended up a victory short of claiming the championship in New York a year ago, when she lost to Gauff in front of a rowdy partisan crowd.

This time, against another American, the 13th-seeded Navarro, Sabalenka didn’t let the fans play much of a role until things got interesting down the stretch. Sabalenka joked after her previous match she would try to sway them to her side by buying booze, saying, “Drinks on me tonight? ”

Navarro did not fold in the second set, despite trailing for much of it, and as the noise around her grew, she broke when Sabalenka attempted to serve for the victory at 5-4.

“I wasn’t ready for the match to be over,” Navarro said.

But in the tiebreaker that followed, Sabalenka took over after Navarro led 2-0, grabbing every point that remained.

“I kind of got my teeth into it there at the end of the second set,” Navarro said, “and I felt I could definitely push it to a third. Wasn’t able to do so.”