72hrs Free Transit, do I need to get a visa if we decide to get out of the airport on our way back?

Leaving LAX to Manila on Nov 18 and we have a 15hrs layover in Beijing and I am planning to utilize that 72hrs transit free on that leg. My question though, we are flying back from Manila to LAX on Nov. 27 and have a 9hrs stop over in Beijing, do I need a visa for that? or that's covered within 72hrs transit free since it's another layover from a different flight?