Flying from Kathmandu transit through Chengdu and stop-over in Beijing and the Stockholm

On my way to Stockholm (Kathmandu-Chengdu-Beijing-Stockholm), I want to do a stop-over in Beijing for two days since after 1st of January one can stay for a maximum of 72 hours in Beijing without a visa. I will stay less than 72 hours in total transit time on the way back, considering both transit in Chengdu and Beijing. According to information I found in various places I do not need a visa if 1) I spend less than 72 hours in transit/stop-over in Beijing (including time between flights in Chengdu), 2) have a valid onward ticket from Beijing to a third country and 3) I stay at the airport in Chengdu. Do I qualify for a 72 hour visa free stay in Beijing? I am just transfering through Chengdu and then to Beijing for less than 72 hours.

Kathmandu – Chengdu 11:30 – 16:45
Chengdu – Beijing 19:00 – 21:40 (Friday)
Beijing – Stockholm 13:50 – 17:20 (Monday)
Time spent in China 2:15 (transit Chengdu) + 2:40 (fly time to Beijing) + 64:10 (stop-over Beijing) = 69:05