Neil Powell’s side won both rounds of the shortened Series after beating Great Britain 24-12 in the final in Edmonton.
This year’s championship was limited to only two tournaments in Canada because of the pandemic.
Great Britain finished as runners-up, level on points with Kenya who lost to South Africa in the Vancouver final.
Hosts Canada finished fourth overall, two points ahead of USA.
Hong Kong signed off by beating Ireland to finish seventh in Edmonton. Tries from Hugo Stiles, Max Denmark, and Liam Herbert gave the SAR a 21-14 victory and back-to-back seventh-place finishes in Canada.
Hong Kong finished level on points with seventh-placed Germany in the final standings.