Hongkong - Shanghai - Manila

Hi I'm flying from Hong Kong to Shanghai, stay there less than 72h and will then fly to Manila. My question is if I get the 72h visa, cause the flight to Manila goes via Hong Kong airport, but I'm not leaving the airport, so I'm there in the 'transit-zone', therefore my third country is Manila. I went to the Chinese embassy, she said it should be alright, but I want to be sure! Can you help me?