Although Sabalenka and Magda Linette of Poland will be playing in their first semi-finals at Melbourne Park, Azarenka returns to final-four action after a decade away when she takes on Wimbledon champion Elena Rybakina.
Now a self-confessed "obnoxious" soccer mom, the 33-year-old Azarenka looked every inch the player who won back-to-back Australian Open titles in 2012 and 2013 when she took apart in-form third seed Jessica Pegula in the quarter-finals.
Russian-born Kazakh Rybakina, seeded 22nd only because no rankings points were handed out at Wimbledon last year, is also in hot form after taking out world number one Iga Swiatek in straight sets and last year's runner-up, Danielle Collins.
"It will be a great matchup," said Belarusian Azarenka, who lost their only meeting in straight sets at Indian Wells last year. "I'm looking forward to having that challenge. She's an incredible player ... her ranking obviously doesn't tell the full story."
Sabalenka's form this year has been on another level and she will take to Rod Laver Arena on Thursday having won nine consecutive matches without dropping a set since the start of the season.
Her run to the title-decider at the WTA Finals to end last year further indicated that she has finally found the mental stability on court to go with her considerable weapons, most notably a huge serve and a thunderous forehand.
The 24-year-old knows she will have to take her fifth seeding with a pinch of salt against Linette, who has emerged from nowhere at age 30 to reach her first Grand Slam semi-final, knocking out fourth-seeded Caroline Garcia en route.
BRUTAL LOSS
Linette has lost both of her previous meetings with Sabalenka, including a particularly brutal 6-2 6-1 loss at the Tokyo Olympics two years ago, and said she would be sticking to what has worked for her so far in Melbourne.
"My last encounter wasn't the best at the Olympics," she said. "I will just try what I'm doing this whole week. I'm being very consistent, returning really well, and keeping my serves.
"I think she will be just a little bit more consistent version of being aggressive on every single shot. I will just need to serve really well again."
Sabalenka, who has played three previous Grand Slam semi-finals and lost them all, knows that her biggest battle on Thursday will most likely be with her own emotions.
"I think it's going to be a great test for me, if I can actually keep myself calm in key moments," Sabalenka said.
"I've been in the semi-finals before, and I got there with all those up and downs. All those up and downs didn't help me at all in the semi-finals."
