New Zealand and Fiji have shared victories in the first four legs of the series, but the Kiwis are tied on points at the top with the U.S., which has reached all four finals.
Vilimoni Koroi set up Regan Ware for the opening try by New Zealand, and Ware helped Sam Dickson score the second to lead 14-0 at halftime.
Tone Ng Shiu sold Danny Barrett a dummy for the third try, and the Americans had to be consoled with a Brett Thompson score.
New Zealand also won the women's final, the Black Ferns beating Australia 34-10 for their 48th consecutive match win. Ireland was third.
The New Zealand men reached the final by beating Fiji, which damaged its chances when Sevuloni Mocenacagi was red-carded for a dangerous tackle. Meli Derenalagi was also sin-binned and Fiji was reduced to five, reduced somewhat when New Zealand's Kurt Baker was sin-binned, too. But New Zealand was out of reach by then, and won 36-14.
Fiji eliminated defending Sydney champion Australia in the quarterfinals.
The U.S. beat England 14-7 in the other semifinal.
The series moves to Las Vegas on March 1.