World number one Sabalenka saved five break points to edge a tight opening set against her 17-year-old Russian opponent, who had stunned the then-ailing Belarusian in the French Open quarter-finals seven months ago.
Fit and firing on all cylinders in her opening tournament of the new season, Sabalenka shifted gears in the second set for an early break and eased through to book a meeting with Russian Polina Kudermetova in Sunday's final.
"It's always the same tactic for me, to stay aggressive and put my opponents under pressure," said Sabalenka, runner-up at the tournament last year.
"I was glad I was able to do that against Mirra. It seemed like everything was working really well. She's an amazing player and I'm pretty sure she's going to be in the top 10 very soon. I'm happy to get this win."
Check out the game summary here.
The 21-year-old Kudermetova earlier swept aside Ukraine's Anhelina Kalinina 6-4, 6-3 to continue her stellar run from the qualifying competition.
DIMITROV OUT
Grigor Dimitrov's title defence in the men's event ended when the Bulgarian retired with an injury while trailing 6-4, 4-4 against Czech Jiri Lehecka on Pat Rafter Arena.
Reilly Opelka followed up his stunning victory over Novak Djokovic by beating Frenchman Giovanni Mpetshi Perricard 6-3, 7-6 in a battle of big servers in the other semi-final.
The 6-foot 11-inch (2.11m) American has had a torrid time with injuries in the previous two seasons and he shrugged off a wrist issue in the opening set before edging a tiebreak in the next to reach his first final in three years.