Less than 24-hour stay in Guangzhou

Hi!

I'm a Philippine passport-holder with confirmed flight tickets from Manila > Hongkong (July 16, 2018) and Guangzhou > Manila (July 18, 2018).

I planned to purchase a train ticket from Hongkong to Guangzhou Baiyun International Airport (transit point) on July 17, rounding-up my stay in mainland China for less than 24 hours.

Am I allowed to take the train from Hongkong to Guangzhou on a 24-hour direct transit? Or, do I still need to apply for a China transit (G)?


Thanks in advance,
Johan