The Belarusian began the season by winning a title in Adelaide and is yet to drop a set in 2023 as she bids to win a first grand slam title.
Sabalenka has been knocking on the door for several years, reaching back-to-back semi-finals at the US Open and the last four at Wimbledon in 2021, but is yet to make a final.
Last year she began the season struggling to land her serve in the court but everything appears to have come together and Sabalenka was superb in a 7-5 6-2 victory over 12th seed Bencic, another in-form player, hitting 32 winners and only 18 unforced errors.
Consulting a biomechanical expert proved the key to fixing her serving issues and Sabalenka now sees it as a blessing in disguise.
"I'm super happy that this thing with my serve happened to me," she said.
"Before I wouldn't be really open for that. I would be like, 'You know what, my serve is fine, I don't want to change anything'. Actually, even when my serve was working, it wasn't really right.
"I was, in that moment, open for whatever. I was just like, 'Please, someone help me to fix this f***ing serve. I'm sorry for swearing, but this is how it was."
"I want believe that the way I'm working right now, the way I'm on the court right now, this is the new beginning, and this is the next step. So I really want to believe that it's going to really help me."
The conditions at Melbourne Park this year are clearly favouring the power players and Sabalenka will be a big favourite to make the final from the bottom half, particularly following the exit of fourth seed Caroline Garcia in another upset.
Next up for fifth seed Sabalenka will be a clash with unseeded Croatian Donna Vekic, who ended the run of 17-year-old Linda Fruhvirtova with a 6-2 1-6 6-3 victory.
Vekic was also a former teenage prodigy and made her debut here a decade ago but this is only her second grand slam quarter-final.
Former world number one Karolina Pliskova has slid virtually unnoticed through the draw, reaching the last eight with a 6-0 6-4 victory over Zhang Shuai.
The Czech missed her first grand slam since the US Open in 2012 here last year after sustaining a hand injury.
Pliskova said: "Of course it's amazing just to be here because I was really, really sad last year that I missed especially this part of the season.
"It just took me some while because I also started pretty much still with the pain. I felt like lately I was finding my game. Now I continue playing how I was playing in the US swing. Happy again to be in the quarter-finals second slam in a row."
Garcia ended last season by winning the biggest title of her career at the WTA Finals and arrived in Melbourne as one of the favourites but fell to a shock loss against 45th-ranked Linette.
The Pole, who has unexpectedly gone further than her compatriots Iga Swiatek and Hubert Hurkacz, claimed a 7-6(3) 6-4 victory to make the first grand slam quarter-final of her career.