Just checking

Hi,

I have a EU passport and plan the following.
Traveling from Sydney to Hong Kong, via Shanghai. Spending 20 hours in Shanghai, in the city.
My ticket is confirmed for - SYD, PVG, HKG, PVG, SYD
Then in Hong Kong, after staying there 24 hours, I'm flying back the same route(but now only a 4 hours Shanghai stop over where I'll remain at the airport).
I assume I can make use of the 72 hour transit visa?