The Kiwis crushed South Africa 21-5 at the National Aquatic Stadium to begin Group A with a bang.

Liana Dance scored five times in the match with Nadia Pavlovich, who netted on four occasions, the best player for the hosts.

"We've been doing really well in training games so we're happy to get it all going today," said Pavlovich.

"We're looking forward to tomorrow’s game against Spain but we know we need to pick up the intensity, pick up the passing and our finishing."

New Zealand coach Davor Carevic was proud of his side's result.

"Our girls were stand-outs tonight," he said. 

"They showed real grit and teamwork - they have some tough games ahead but I believe our team showed what they are really made of."

The other match in Group A saw Russia beat Spain 18-6.

In Group C, defending champions the United States began with a big 26-10 win over Japan, with Greece beating China 15-10 in the other game.

The Netherlands edged Italy 16-15 in Group B, a three-team group.

In Group D, Hungary demolished Mexico 29-7 and Canada beat Germany 12-8.

Group play will continue until December 15 with the top side going through to the quarter-finals and the second and third-place teams facing play-offs to progress.

Last eight matches will be played on December 16, with the semi-finals on December 17 before the final on December 18.

The US beat Canada 5-4 in the final of the last edition, held in Spain's capital Madrid in 2014.