The USA claimed the London Sevens title while Fiji were crowned overall World Series champions after the final leg of the season.
Mike Friday's side beat Australia 45-22 to complete a stunning day, having earlier crushed England and Canada to reach the final.
Australia had impressed up until the final, comfortably seeing off first Scotland and then Fiji, but they had no answer against the Americans.
With their combination of sprint duo Perry Baker and Carlin Isles, as well as former Fiji age group player Andrew Durutalo, they were a class above everyone else at Twickenham, claiming their first Sevens World Series title as a result.
Fiji had secured the overall Sevens World Series title by beating South Africa in the Cup quarter-finals to ensure they wouldn't be caught in the overall standings..
A double from Savenaca Rawaca helped them to a 19-7 win as they claimed their first overall Sevens title since 2006 and ended a run of four straight titles for New Zealand.
Australia comfortably saw off Scotland 31-19 in their quarter-final before producing a shock win over Fiji in the semis, 33-7.
The USA were far too strong for England in the other semi-final, running in seven tries in total including braces from Perry Baker, Carlin Isles and Andrew Durutalo in a 43-12 win.
England had previously beaten defending champions New Zealand 21-17 in the quarter-finals while the USA downed rivals Canada 29-10 in the other last eight encounter.
In the Plate final, New Zealand downed South Africa 26-14, while Kenya won the Bowl by beating Argentina 26-12.
Finally it was Japan who were crowned Shield winners, coming from behind to beat France 21-19.
USA 45-22 Australia
Australia 33-7 Fiji
England 12-43 USA
Fiji 19-7 South Africa
Scotland 19-31 Australia
USA 29-10 Canada
New Zealand 17-21 England
Third place play-off
Fiji 26-12 England
New Zealand 26-14 South Africa
South Africa 31-7 Scotland
New Zealand 33-15 Canada
Kenya 26-12 Argentina
Kenya 38-7 Samoa
Argentina 26-14 Wales
Samoa 33-14 Portugal
Kenya 24-12 Japan
Argentina 17-14 France
Wales 29-0 Brazil
Japan 21-19 France
Japan 26-21 Portugal
France 35-12 Brazil