Sevens world series leaders New Zealand, England, Samoa and Fiji opened their Hong Kong accounts with romps on Friday.
Joint leaders New Zealand brushed aside South Korea 61-0, while the English made only one mistake against China in winning 59-5.
Defending champion Samoa cruised past tournament newcomer Mexico 64-0, and fan favorite Fiji dispensed with Malaysia 59-0.
Also, Australia brushed aside Zimbabwe 42-0 and South Africa shrugged off an early scare to overpower Spain 35-5.
Buxton Popoalii led the way for New Zealand with 26 points from two tries and eight conversions.
"Them not crossing our line was pleasing. Not conceding a try was pleasing. In sevens rugby anything can happen so it's important to get out and get a lot of confidence," New Zealand coach Gordon Tietjens said.
"I firmly believe that you set the standard for the tournament by your first game. It looks good going into tomorrow."
England was also in control against China, despite conceding a try Wang Chongyi four minutes in. But England's Ben Gollings, who added to his all-time leading sevens points record with a try and seven conversions, was unconcerned by the slipup.
"We're not going to go home and kill ourselves over it," he said.
"We've got a whole day of rugby tomorrow and it's a great victory for us. We're happy and we'll move on."
Group results from the Hong Kong Sevens rugby tournament on Friday:
New Zealand 61 South Korea 0
Portugal 12 France 5
England 59 China 5
USA 24 Japan 19
Samoa 64 Mexico 0
Scotland 12 Tonga 10
Fiji 59 Malaysia 0
Russia 22 Kenya 5
South Africa 35 Spain 5
Wales 35 Hong Kong 12
Australia 42 Zimbabwe 0
Canada 22 Argentina 21