Madison Keys will face Aryna Sabalenka in Saturday's Australian Open final after the American stunned in-form Iga Swaitek in their last four clash at Melbourne Park.
World No 2 Swiatek went into the clash as clear favourite having not lost a set in five matches and only dropping 14 games along the way.
And the five-time Grand Slam champion looked on course for a first appearance in the final Down Under after winning the opening set.
But 13th seed Keys hit back taking the second in style before going on to save a match point in the decider, winning 5-7, 6-1, 7-6 after a 10-point tiebreak at the Rod Laver Arena.
It was the fourth time in this year's tournament that Keys had come through in three sets and now plays in her second Grand Slam final, having lost to compatriot Sloane Stephens at the 2017 US Open.
Swiatek had not dropped her serve since the first round but was broken eight times by Keys, who finally won a marathon battle in two hours and 35 minutes.
“I’m still trying to catch up to everything that is happening, I’m in the finals,” said the 29-year-old in her on-court interview. “That match was such high level and she played so well and I just felt like I was fighting to stay in it.
“I then ran with the second [set] and the third was just a battle and to be able to be standing here and be in the finals is absolutely amazing and I’m so excited that I get to be here on Saturday.”
It was a draining battle for both players but keys revealed that she never lost hope despite having to come from behind to win the match.
“I feel like even though I lost the first set I was playing some better tennis at the end of it and that I had a little bit of momentum going into the second set,” Keys added. “To be able to run with that second set and really just be able to settle was really nice.
“In the third set it was so up and down and there were so many big points and break point chances that neither one of us got.
“I feel I blacked out at one point and I was just there running around so just to be able to stay in it and stay fighting, and then a ten-point tiebreaker for an extra dramatic finish.”
Earlier, Sabalenka triumphed first in Melbourne when she defeated close friend Badosa 6-4, 6-2.
The hard, fast courts of Melbourne Park have been the 26-year-old's happy place. She has now won 20 straight matches at the Australian Open to close in on a third consecutive crown – something that has not been achieved this century.
The last person to do so was Martina Hingis in 1999 and only four other women have completed the three-peat – Margaret Court, Evonne Goolagong, Steffi Graf and Monica Seles.
"I am so proud of myself. I'm proud of my team that we're able to put ourselves in such a situation,” Sabalenka said of being on the cusp of a third title.
“It's a privilege, you know. If I'm able to put my name into history, it will mean a lot. It will mean the world to me.”
Sabalenka last year described Badosa as her “best friend” and “soulmate” and said she was “super happy” that they got to play each other on such a big stage.
“A tough match, tough battle,” she said. “I hope she's still my friend. I'm sure she'll hate me for the next hour, day or two, but I'm OK with that, I can handle that.
“After that I think we are back to being friends, back to go out together and go shopping.”
Despite losing, Badosa's run to the last four capped a remarkable comeback after a brutal back injury in 2023 left her considering quitting tennis.
Instead, her Melbourne exploits will return her to the top 10 for the first time since October 2022. Keys will also return to the top 10.
