Qualification for TWOV

Sylvester, your itinerary, under the condition that Guangzhou is your only stop within mainland China and if you are traveling to Guangzhou from some other country, different than both China and Australia, you are definitely eligible for 24 hour visa free transit and you don't need any kind of visa.

You will print out your flight tickets and have those printouts with you. Also, you will declare in your origin country from where you will arrive in Guangzhou that you will travel to Sydney via Guangzhou using 24 hour visa free transit. After a short inspection of your tickets, you will be allowed to board the plane.

Upon arrival in Guangzhou, you will approach 24 hour visa free transit counter where you will apply for a temporary entry permit to be allowed to make a transfer from one to another flight. Assuming that you are flying on separate tickets, this permit will be granted to you or one of airport staff will escort you until your boarding gate for your flight to Sydney.