By SABC Sport
25th January 2025
The 29-year-old also had to defeat Iga Swiatek in the semi-finals, meaning she defeated the world's top two players in successive matches and thoroughly deserved the title.
Keys made an outstanding start to surge to a 5-1 lead before she served out the opening set at the second opportunity.
Sabalenka, who was trying to win a third consecutive Australian Open title and a fourth major, responded by breaking twice en route to winning the second set convincingly.
Keys then edged a close and high-quality third set to seal a stunning win when she converted her second championship point as Sabalenka served at 5-6.
At the age of 29 years and 342 days, Keys has become the oldest woman to defeat the top two players in the world at a Grand Slam since the WTA Rankings were introduced in 1975.
The American is the fourth-oldest first-time women's singles Grand Slam champion in the Open era after Flavia Pennetta, Ann Jones and Francesca Schiavone.
At the trophy ceremony, Keys said: "Bear with me because I'm absolutely going to cry. There is no way I get through this without tears, so sorry in advance!
"Firstly, Aryna you are an unbelievable player and I'm glad I got you back.
"You are always so tough to play against and we always have the craziest matches. Congratulations to you and your team for another amazing Grand Slam run.
"Thank you to everyone who came out and cheered the last two weeks. I always feel so at home here.
"I made my very first Grand Slam semi-final here in Melbourne, so to have won my first Grand Slam in the same place means the absolute world to me.
"I just want to say thank you to my team - this is where I'm going to cry - I have wanted this for so long.
"I've been in one other Grand Slam final and it didn't go my way, and I didn't know if I was going to be able to get back into this position to win a trophy again.
"My team believed in me every step of the way. They believed in me when I didn't believe in myself and helped me every step of the way.
"I love you all so much and I cannot wait for more. I just want to say thank you so much. I'm so appreciative towards every single person who helped me continue to believe in myself and push on to achieve this dream."