ORD - PEK - HKG (24 hours) - PEK (12 hours) - ORD. Would the 72 hour visa free transit apply?

I am flying ORD - PEK on April 27 and PEK - ORD on April 30. Can I buy a ticket from PEK - HKG on April 27 and return on April 29 to PEK with about 12-15 hours between arriving in PEK and the return flight to the ORD on the 30th. I know it would on the outbound but with the overnight connection between in PEK before returning to the USA I was not sure.

Thanks,
John