BKK-PEK-ICN-BKK

Hello,

I plan to do this itinerary:

BKK-PEK direct flight, stay in PEK for about 70 hours. Then, PEK-ICN-BKK. Time in ICN is about 2 hours. I won't be leaving ICN airport, just transiting there, changing planes to BKK.

Does this work for 72 hour transit?
Please note that I hold a passport from one of the 53 countries that can enjoy 72-hours free Transit.

Thanks.