Entering Guangzhou by plane, and taking the train to Hong Kong

Hi everyone! I'm just checking to see if it's alright for me to fly into Baiyun airport in Guangzhou, and leave the airport to take the train to Hong Kong within 4 hours. (My ongoing flight from Hong Kong is to Haikou, where I think visa-on-arrival is permitted.)

Do I qualify for the 24 hour direct transit? Will I need to apply for the temporary stay permit?