Seat reservation

One of the requirements is 'a ticket to a third country with confirmed seat and date'. Since I am only able to check in 48h before my flight, I won't have my ticket with reserved seat to a third country at arrival in China. I will have an itinerary of all my flights (with reference number) and will check in 48h before my flight. Am I still eligible for a 72h visa free transit (without a ticket with a reserved seat but with the itinerary) or do I need to apply for a tourist visa?