Hello 2 Days in Beijing

No you do not qualify if your route is Seoul-Beijing-Guangzhou-Australia. Two stops in China limits you to 24 hours transit unless you have a visa.

Thank you, hector! Therefore, i need to exit china via beijing only or hk would qualify? What is the quickest way to get a chinese visa for an australian national? Regards, jm.

Both Beijing-AUS and Beijing-HK-AUS will work. For the latter, you also exit China from Beijing as HK is a separate immigration jurisdiction.
OTOH getting a visa would normally take 4 business days but you may be able to apply for rush service which reduces the time by 2 or 3 days for a fee. What you should consider is whether whether the cost for a visa will exceed the cost of changing your plane ticket, or vice versa.