MEL to HangZhou then Shanghai to Vietnam

Hi,
I am planning to take Xiamen Airline, and stop at HangZhou airport. Then take off at Shanghai airport to Vietnam. As I take Xiamen Airline, they will stop at Xiamen international airport for couple of hours to pick up some passengers before flying off to Vietnam. My question is whether I can still apply for the 72 hr free visa when I stop at HangZhou? Thank you.