The world No.1 beat Rybakina to win her maiden grand slam title at the Australian Open in 2023 but since then had lost all four finals against the Kazakh, including at the WTA Finals last season and in Melbourne in January.
Sabalenka said after winning her semi that she was "so done" with losing big finals, and she saved a match point in the deciding tiebreak to come through 3-6 6-3 7-6 (8-6) on Sunday.
After celebrating on court with her fiance and new puppy, Sabalenka said in her on-court interview: "What a week - getting a puppy, getting engaged and winning a title. I will definitely remember it for the rest of my life."
Rybakina was on a 12-match winning streak against top-10 opponents and she looked in control of the contest at a set and a break up.
Sabalenka, who also lost two slam finals last year, turned the second set around and won four games in a row to force a decider.
This was a first-strike battle of power tennis, and it was Sabalenka who drew first blood in the third set, breaking serve in the third game.
But the pressure from Rybakina was growing and the Belarusian was unable to serve it out when she stepped up at 5-4.
When her opponent, who will leapfrog Iga Swiatek to become world No.2 on Monday for the first time, saved five break points in the next game, Sabalenka must have feared the worst.
However, she did not allow her emotions to overwhelm her, calmly saving a match point at 5-6 in the tiebreaker with a series of crunching backhands and seizing her first opportunity to win the title.
16°C