Sabalenka ended a frustrating run of finals futility against Rybakina, who had won their last four title clashes, starting with a triumph at Indian Wells in 2023 and including a nail-biter at the Australian Open in January.
Sabalenka rallied from a break down in the second set and fought off a match point trailing 5-6 in the tiebreaker before finally gaining the longed-for title - and a healthy measure of revenge.
"Thanks God I got this trophy," said Sabalenka, who lost to Russian teen Mirra Andreeva in last year's final.
She had appeared on her way with a break for 2-1 in the third set. But Rybakina piled on the return pressure to break back for 5-5 and fought off five break points in the next game.
Deflated but determined, Sabalenka held at love to force the tiebreaker, rallying from 3-5 down before saving match point with a stunning backhand winner. She won the net point on Rybakina's serve and delivered another massive serve herself to seal it.
"It was a hell of a battle," Sabalenka said.
"I'm super-happy with the last three points of the match that I was able to pull out such great tennis."
The latest clash between the big-serving, bit-hitting rivals was again a match of razor-thin margins.
Rybakina converted the only break point of the opening set for a 4-2 lead and backed up the break with a love game.
It wasn't until she served for the set that Rybakina lost two points in a service game. But after falling behind 0-30, she powered back, giving herself a set point with an ace and pocketing the set when Sabalenka's backhand down the line slipped wide.
A double-fault on break point in the opening game of the second set left Sabalenka in a world of trouble.
But despite her obvious frustration, Sabalenka dug in, winning the next four games to take a 4-1 lead.
"The whole idea going into this match was to be mentally strong, to stay strong no matter what, to show with the body language that I'm here, I'm fighting, and no matter what's going on right now in the match, I'll still be fighting," Sabalenka said.
She broke Rybakina at love to level the set at 1-1 and saved two more break points in a marathon third game.
Rybakina, her forehand errors rising along with the desert heat, double-faulted on break point to hand Sabalenka a 3-1 lead, Sabalenka holding with ease to make it 4-1 before Rybakina stopped the rot.
Sabalenka had to fend off a break point for 5-2 and saved another one with an ace as she served out the set.
Sabalenka will now head into her Miami Open title defence aiming to complete the 'Sunshine Double'.
Rybakina will arrive in Miami ranked second in the world, climbing one spot to overtake Poland's Iga Swiatek.