Former world number one Karolina Pliskova defeated China’s Zhang Shuai 6-0, 6-4.
Sabalenka never really looked like she would knock out top seed Iga Swiatek, Garcia and the rest in the first major of the year.
Belarusian Sabalenka and third-seeded American Jessica Pegula – both chasing a major major crown – are now the women to beat.
Sabalenka beat formidable 12th seed Belinda Bencic 7-5, 6-2 to set up a last-eight clash against unseeded Donna Vekic, who defeated 17-year-old Linda Fruhvirtova in three sets.
The hard-hitting Sabalenka entered her first quarterfinal at the Australian Open and said, “My whole life, it took me a while to understand that negative emotion won’t help you on the court.
“You just have to stay strong and believe no matter what, and then do everything you can.”