The world number one saw off the awkward Bai 6-3, 6-1, having threatened at one stage to complete the job in even more express fashion.
Britain's 2021 US Open champion Raducanu plays Russia-born Austrian Anastasia Potapova later Wednesday at Melbourne Park, with Sabalenka lying ominously in wait.
Sabalenka is favourite to win a third Australian Open in four years, having been defeated in the final 12 months ago by Madison Keys.
"Tricky opponent," said the Belarusian.
"Super-happy to close the (first) set... Читать дальше...