MELBOURNE: When Madison Keys finally finished off her 5-7, 6-1, 7-6 (10-8) upset of No. 2 Iga Swiatek in a high-intensity, high-quality Australian Open semifinal on Thursday night, saving a match point along the way, the 29-year-old American crouched on the court and placed a hand on her white hat.

She had a hard time believing it all. The comeback. What Keys called an “extra dramatic finish.” The victory over five-time Grand Slam champion Swiatek, who’d been on the most dominant run at Melbourne Park in a dozen years. And now a chance for Keys to play in her second Grand Slam final, a long wait after being the 2017 US Open runner-up.

“I’m still trying to catch up to everything that’s happening,” said the 19th-seeded Keys, who will face No. 1 Aryna Sabalenka, the two-time defending champion, for the trophy Saturday. “I felt like I was just fighting to stay in it. ... It was so up and down and so many big points.”

Just to be sure, Keys asked whether Swiatek was, indeed, one point from victory, acknowledging she really had no idea. Yes, Madison, Swiatek was that close to ending things while serving at 6-5, 40-30, but missed a backhand into the net, then eventually getting broken by double-faulting, sending the contest to a first-to-10, win-by-two tiebreaker.

“I felt like I blacked out there at some point,” Keys said, “and was out there running around.”

Whatever she was doing, it worked. Keys claimed more games in the semifinal than the 14 total that Swiatek dropped in her five previous matches over the past two weeks.

“It was a matter of one or two balls,” said Swiatek, who lost in the Australian Open semifinals two years ago, too. “Madison was kind of brave.”

Sabalenka beat good friend Paula Badosa 6-4, 6-2 earlier Thursday. Sabalenka, a 26-year-old from Belarus, can become the first woman since 1999 to complete a threepeat.

“If she plays like this,” the 11th-seeded Badosa said, “I mean, we can already give her the trophy.”

Keys might have something to say about that.

Still, Sabalenka won her first major championship at Melbourne Park in 2023, and she since has added two more — in Australia a year ago and at the US Open last September.

The last woman to reach three finals in a row at the year’s first Grand Slam tournament was Serena Williams, who won two from 2015-17. Martina Hingis was the most recent woman to win three titles in a row in Melbourne, doing it from 1997-99.

“I have goosebumps. I’m so proud of myself,” said Sabalenka, whose 4-1 head-to-head record against Keys includes a win in the 2023 US Open semifinals.

Swiatek had not lost a single service game since the first round, but was broken three times by Keys in the first set alone and eight times in all.

That included each of Swiatek’s first two times serving, making clear right from the get-go this would not be her usual sort of day. And while Swiatek did eke out the opening set, she was overwhelmed in the second, trailing 5-0 before getting a game.

This was the big-hitting Keys at her very best. She turns 30 next month and, at the suggestion of her coach, former player Bjorn Fratangelo — who also happens to be her husband — decided to try a new racket this season, an effort both to help her with generating easy power but also to relieve some strain on her right shoulder.

It’s certainly paid immediate dividends. Keys is now on an 11-match winning streak, including taking the title at a tuneup event in Adelaide.

She was good enough to get through this one, which was as tight as can be down the stretch.

“At the end, I feel like we were both kind of battling some nerves. ... It just became who can get that final point and who can be a little bit better than the other one,” Keys said. “And I’m happy it was me.”

Sabalenka trailed 2-0, 40-love at the start but quickly figured things out, especially once Rod Laver Arena’s retractable roof was shut in the first set because of a drizzle. She straightened her strokes and overpowered Badosa, who eliminated No. 3 Coco Gauff to reach her first major semifinal.

“She started to be very, very aggressive,” said Badosa, who thought about retiring last year while dealing with a stress fracture in her back. “Everything was working.”

Sabalenka and Badosa did their best to avoid any eye contact for much of the evening, whether up at the net for the coin toss or when they crossed paths at changeovers.

When their match was over, they met for a lengthy hug.

During Sabalenka’s on-court interview, she joked about taking Badosa — who by then was sitting in a hallway, her head bowed — on a shopping spree to make things up to her, paying for whatever the Spaniard wants.

Told what Sabalenka said, Badosa noted: “It’s going to be something really expensive.”