tourist 1-entry visa - planning trip to hk

I am going to visit my sister who lives in beijing, and already have received my 1-entry tourist visa from cvasc in germany. we would like to go to hong kong for the weekend but i only have one entry, so at first this seemed difficult. now with the 72-hrs visa free stay, is it possible? i would get back on apr 6th from hong kong and fly out to zurich on the 8th in the morning. do i qualify for a 72-hour free stay?