It was an impressive finish to the tournament by the Black Ferns, as much for the eight tries in the wet as the clean defensive sheet, missing just seven tackles and, for the second consecutive game, not conceding a try.
Leading the charge on attack was left wing Ayesha Leti-I’iga, who ran in a dynamic hat-trick and was in irrepressible mood. Halfback Arihiana Marino-Tauhinu relished her first Test start and was named player of the match. She was busy and effective, set up at least two tries and worked some incisive angles and inside balls for her forward runners.
Others to stand out included lock Chelsea Bremner and fullback Renee Holmes, who is making a strong case to be the first-choice fullback with her penetration on attack.
The Black Ferns led 29-6 at the half, playing at a good tempo and with serious intent and endeavour. USA struggled to stick with them even if they did force errors in the slippery conditions, while its scrum, led by loosehead prop Hope Rogers, gave the Black Ferns some heat on several occasions.
But the USA could offer little on attack in the face of staunch defence from the home side, who had their line crossed just once in three games.
The scoring started early, Leti-I’iga roaring in off a bust from Ruahei Demant and the last pass by Holmes. Lock Joanah Ngan-Woo then set up Marino-Tauhinu and the Black Ferns firmly held the initiative at 12-3. There was good interpassing in the forwards and some clever variations off lineouts.
There was time before oranges for another to Leti-I’iga, shrugging off a would-be tackler and gapping it, while Holmes raced 60m to score off a turnover. Second five Sylvia Brunt ran a sweet line off Marino-Tauhinu.
Lucy Anderson was on at halftime for her long-awaited Test debut, to join starting debutante, hooker Natalie Delamere, with her first cap.
The Black Ferns ran in three second half tries, the first showcasing Kendra Reynolds’ speed and fend, the second to Leti-I’iga, who danced her way over from 35m, and third to Renee Wickliffe to help raise the half ton. This was set up by Holmes and Chelsea Semple.
Prop Krystal Murray, a favourite for mayor of the north according to one banner, was binned for a borderline high tackle.
Best for the USA were industrious flanker Rachel Johnson and solid prop Rogers.
In the first clash of the Pac Four double-header, Canada adapted better to the wet conditions in downing the Australian Wallaroos 22-10, manufacturing a second stanza comeback after trailing at the break. Canadian No 8 and skipper Sophie de Goede was again prominent and was adjudged player of the day.
The Wallaroos will face the Black Ferns twice in August for the O'Reilly Cup.
Black Ferns 50 (Ayesha Leti-I’iga 3, Arihiana Marino-Tauhinu, Renee Holmes, Sylvia Brunt, Kendra Reynolds, Renee Wickliffe tries; Hazel Tubic 3 con, Ruahei Demant con, Holmes con) USA 6 (Megan Foster 2 pen) HT: 29-6 Black Ferns