Stopping over in HK on outbound flight

Hello there,
I am intending to stop over in Chengdu for 72 hours, flying from the UK.
My onward ticket is to Australia (Chengdu-HK (layover 3 hours)-Sydney).
Is it a problem that I will change planes in HK? My outbound flight (Chengdu-HK-Sydney) is all the same international ticket.
I'd be grateful for some advice.