72 hours free visa question

Hello, glad to see lots helpful tips on your website.
That said, can you please advise if my itinerary below falls on the free 72 hours? I believe the time frame fits, but a second opinion from experts will lessen my worries. I am flying from Manila to San Francisco via Beijing (PEK) & providing myself enough time to see the Great Wall and other places.
Thank you- Juels

Sat, Oct 14 from Manila (MNL) - Beijing (PEK) = arrive 10:30a
Mon, Oct 16 from Beijing (PEK) - SFO - depart 3:40p