ICN-PVG-SYD (via ICN) Itinerary eligible for 72hrs visa?

Hi, I'll be flying in to Shangai on an Australian passport from Seoul and my next and final destination is to Sydney. Staying from in Shanghai from Friday 1.30pm to Sunday 1.35pm (48hrs). As I'm flying with Korean airlines, my Shanghai-Sydney route will be connecting via Seoul airport (again) for approx. 2 hours and but I'm not exiting Korean Immigration.