"When someone like Portia Woodman's got her hands on the ball then she is going to score", Hong Kong coach Jo Hull said.
The winger scored four tries in 11 minutes towards the end of the game, as the Black Ferns began to run riot.
There would be no let-up in the second half as New Zealand ran in a further 10 tries, with Woodman claiming half of the tally. The scrum-half Kendra Cocksedge scored a try and converted 13 of the tries.
The centre Theresa Fitzpatrick scored twice, while there were also tries for Carla Hohepa, Charmaine McMenamin, Chelsea Alley, Hazel Tubic, Sosoli Talawadua, Lesley Ketu, Kelly Brazier and Stacey Waaka.