Hi, I am planning to travel from SYD to PEK, stop over in PEK for four days

and then continue my trip to Hanoi (Vietnam).

Since I have an Italian passport, I can enter Vietnam without an entry permit and stay up to 15 days. Would NOT having a visa for a third country (Vietnam) in my passport still allow me to benefit of the 144-hour Free Transit during my stopover in China?

Thanks,
Mario