In their first rematch on Australian shores since losing to Keys for the Open title last year, the world No.1 found redemption with a 6-3 6-3 triumph at Pat Rafter Arena.
Sabalenka will meet Karolina Muchova in a semi-final to continue her Brisbane title defence, after the Czech talent knocked out third seed Elena Rybakina earlier on Friday.
The four-time grand slam winner dominated Keys with her first serve and made just three unforced errors to take the opening set.
A determined Keys recovered from match point down on her serve, but Sabalenka wouldn't be denied and won in an hour and 29 minutes.
Sabalenka has now claimed two straight-sets victories over the world No.7 since losing last year's Australian Open final in three sets.
The 27-year-old steamrolled her American rival with a 6-0 6-1 semi-final win at Indian Wells last year.
"I know that I lost in Australia against her and that's the big motivation, of course, to go out and to get the win," Sabalenka said.
"But I never stay in the past and never remember things from the previous meeting.
"I know that I have to be focused from the beginning until the end with her because she's an incredible fighter, and she can come back any time.
"When I won the match, of course, I was super happy, but I didn't really have the throwback to the Australian Open last year, to be honest."
Sabalenka had the same line of thinking when asked about her three-match losing streak against semi-final opponent Muchova.
"It doesn't matter if I'm the one who's leading head-to-head against the player or I'm the one who's losing, I don't care," Sabalenka said.
Czechia's Muchova was the first woman to reach the final four after pulling off a 6-2 2-6 6-4 quarter-final win over Kazakhstan's world No.5.
Rybakina, the 2022 Wimbledon champion, lost her serve twice in a nightmare start against Muchova, making 16 unforced errors and three double faults in the opening set.
Elsewhere, American Jessica Pegula beat Liudmila Samsonova 6-3 7-6 (7-3) and will play in-form Ukrainian Marta Kostyuk, ranked No.26 in the world.
Kostyuk backed up Thursday's straight-sets win over world No.3 Anna Anisimova by upsetting 18-year-old world No.9 Mirra Andreeva 7-6 (9-7) 6-3.
In the first of the men's quarter-finals, Aleksandar Kovacevic, who upset Nick Kyrgios and Cameron Norrie earlier in the week, claimed a 7-6 (7-3) 4-6 6-3 win over France's Giovanni Mpetshi Perricard.
The American will face compatriot Brandon Nakashima, who beat Belgium's Raphael Collignon 6-3 6-3.
Alex Michelsen made it three American men into the final four, beating compatriot Sebastian Korda 6-3 7-6 (9-7).
Top seed Daniil Medvedev and Polish lucky loser Kamil Majchrzak were to fight for the last remaining semi-final berth later on Friday.
