Powerhouse winger Aeysha Leti-I'iga had a hat-trick of tries and the Black Ferns put a half-century of points on the USA, as they preserved their unbeaten record in the Pacific Four series.
After sweeping aside Australia and Canada, the NZ women sought victory over the Americans to put the icing on their first campaign under new 'director of rugby' Wayne Smith and achieved that with style in conditions that barely lent themselves to high scoring at Whangārei.
After a brace of tries against the Aussies, Leti-I'iga again showed her power and pace for three more, as her team overran their rivals 50-6. She needed just two minutes to open the scoring, after captain Ruahei Demant's midfield break gave her space out wide.
Leti-I'iga crossed again midway through the first half, when she received the ball and looked to offload, before realising she had an open line ahead of her.
Her third was perhaps the best, with halfback Arihiana Marino-Tauhinu running off a ruck and flicking a delightful pass behind her, as her winger powered through a channel and wrongfooted the last defender to score.
With Smith giving his entire squad a run, Marino-Tauhinu finally logged a test start, after languishing in the shadow of veteran Kendra Cocksedge, and made the most of that opportunity to win player-of-the-match honours.
She had the second try of the night, when lock Joana Ngan-Wood stormed into the 22 and found her halfback running a perfect support line. Fullback Renee Holmes scored, when winger Renee Wickliffe's thunderous tackle dislodged the ball in the Ferns half and Holmes gathered to race away.
When teenager midfielder Sylvia Brunt scored on halftime, New Zealand held a 29-6 advantage at the break and scored three more tries - all converted by Hazel Tubic - over the final 40 minutes to impose themselves on the hapless Americas.
USA gave their opponents everything they could handle at scrumtime and the Black Ferns will need to tidy up their lineout throwing, but they again maximised their running opportunities in foul conditions.
Their next outing is scheduled for August 20 against Australia at Christchurch's Orangetheory Stadium.
NZ 50 (Leti-I'iga 3, Reynolds, Wickliffe, Holmes, Brunt & Marino-Tauhinu tries; Demant, Tubic 3 & Holmes conversions) USA 6 (Foster 2 penalties)
