Third region qualification question

Just looking for clarification on the 144 hour visa free third region qualification. We are planning flying from Australia to Singapore, embarking a (21 day) cruise in Singapore which disembarks in Shanghai. We would then like to enjoy the (6) day private Shanghai transit tour. My question is, to qualify for the 144 hour visa free, do we then have to fly to say Hong Kong and stay, or can we fly home directly from Shanhai back to Australia?