Sabalenka won 77 per cent of her first-serve points, fired down six aces, saved all four break points faced and converted four of her five break point chances during the 71-minute match.
The Belarusian top seed, who resides in South Florida and arrived in Miami fresh off a runner-up finish at Indian Wells, has not dropped a set in her five matches.
"Super-happy that I was able to give myself another chance, another final, another opportunity to hold a trophy," Sabalenka said.
"She's an incredible player so I knew I would have to work for every point.
"I focused on my serve and tried to hit as low as possible because she hits flat. Super-happy with the level I played."
She will face No.3 seed Jessica Pegula in Saturday's decider, a rematch of the 2024 US Open final won by Sabalenka.
Pegula had to be spectacularly resilient to stop the history-making run of the 19-year-old lefty from the Philippines, Alexandra Eala.
The American scored a rollercoaster 7-6 (7-3) 5-7 6-3 win in two hours 26 minutes.
Eala blew kisses to the crowd that gave her a standing ovation after sharing a warm exchange with Pegula at the net.
The Hard Rock Stadium fans had been rooting on the player who had taken out major champions Jelena Ostapenko, Madison Keys and Iga Swiatek previously.
Pegula battled back from 5-2 down to win the opening set and was up a break in the second before the teenager levelled the match despite twisting her ankle during a point.
But Pegula's experience shone through in the decider and she prevailed in a thriller that finished well past midnight, with the 31-year-old writing, "I'm tired" on a camera lens.
"It's nice to know I can win these big matches in really clutch, pressure moments and come out on top," said Pegula, who will compete in her sixth WTA 1000 final.
"One of the people who does it better than me is Aryna. I'm going to have a big battle."
With the AP.
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