Do separately booked flights count?

Hey, i've booked a week in Guangzhou before going to New Zealand, but completely messed up and didn't know I needed a visa for China. Will another flight booked separately still be valid for a connection? I'm planning to spend under 72 hours in Guangzhou when I arrive and then get a plane to Hong Kong for the other 4 days where I don't need a visa. I will then travel back to Guangzhou but this time only spending 6 hours waiting for my next flight to NZ.

Many Thanks
Andrew