The world champion South Africans, host New Zealand and Olympic champion Fiji all finished with unblemished 3-0 records from pool play while Kenya topped the tight Pool D with two wins and a draw.
It first beat Pacific rival Samoa 12-10 in the quarterfinals, then hosts 14-12 in a thrilling semifinal. entered the gold medal match with a 9-6 record in 15 previous World Series finals meetings against and extended that to become the fourth different victor in four tournaments on this season's World Series.
As they had done in Sydney last week, England fell at the quarter-final stages despite pushing New Zealand close.
Fiji beat New Zealand 14-12 while South Africa edged out Australia 24-5 in their Cup semi-finals.
Up next will be the Las Vegas sevens.
While speedy as always in attack, it was the Fijians' defence that secured them the Waikato crown, repeatedly dominating the breakdown against both the All Blacks Sevens and the Blitzbokke and keeping them on the back foot.
After Australia's hopes of a second consecutive tournament victory were dashed in their semi-final loss to South Africa, stand-in captain James Stannard sent over a 20-metre penalty drop goal after the siren to claim a nail-biting 8-7 win over New Zealand in the third-place playoff on Sunday.
"We had to believe in that and we got momentum in the tackle and in the contact areas".
After winning all three of their pool matches on the tournament's first day Saturday, posted two cliff-hanging wins in the knockout rounds to make its way to the final.
The Canadian men, who stand 10th overall after three events, lost 28-14 to the seventh-ranked Americans, 19-14 to No. 9 Kenya and 22-14 to No. 11 Samoa.
England beat Russian Federation 47-0 and Papua New Guinea 27-0 before falling to South Africa in the pool decider.
A superb second half performance saw the Fijian team storm back, with Alasio Sovita Naduva finishing the match with a hat-trick of tries, helping his team to a dramatic 24-17 win.