BMW Oracle blew Alinghi away to win the America's Cup on Sunday.
The victory returns the oldest trophy in international sport to the United States for the first time since 1995.
It was the second race won by the US team in a best-of-three series off Valencia, Spain.
The Swiss catamaran, with Ernesto Bertarelli at the helm, was penalised before the start of each race.
Larry Ellison, the 65-year-old software tycoon whose fortune made the victory possible, was onboard his incredibly fast craft on Sunday, after sitting out Race 1 on Friday due to a weight limit.
But the true star of the day was Oracle's monster black-and-white trimaran and its radical 223-foot wing sail, which powered the craft at three times the speed of the wind, sending its windward and middle hulls flying well above the water.
The American trimaran took a 28-second lead rounding the first mark and then accelerated over the Mediterranean while sailing across the wind on the second leg, its windward and middle hulls flying out of the water.
The final margin was 5 minutes, 26 seconds. Alinghi had to do a penalty 270-degree turn at the finish, the result of errors made at the start of both races.
The two billionaires have been locked in a tumultuous legal fight for two years, and it looked for a while like the race would never make it to the water.
Ellison's victory ends one of the most bitter chapters in the 159-year history of the America's Cup, which has often been a clash of egos as well as boats.
He and Bertarelli fought over their interpretations of the 1887 Deed of Gift, which governs the America's Cup. Ellison's syndicate eventually prevailed.
The combination of deep pockets, technological wizardry and sailing skill eventually delivered a win on the water to BMW Oracle.
Alinghi raised a red protest flag on its giant catamaran late on the first leg of the triangle course. The Swiss dropped the protest after the race, confirming Ellison's win.
Ellison called the victory an "absolutely awesome feeling". "I'm very proud to be a part of this team," he said.
The America's Cup has been away from US shores for 15 years, the longest drought since America won the silver trophy by beating a fleet of British ships around the Isle of Wight in 1851.
swissinfo.ch and agencies
The America's Cup is the oldest and most prestigious trophy in the sport of sailing. It is awarded to the winner of a series of regattas between the defender of the cup and the challenger.
The competition, held for the first time in England in 1851, was won by America, with a boat from the New York Yacht Club. The club held the cup for 132 years until it was beaten in 1983.
By defeating the defending champion, New Zealand, in 2003, Alinghi brought the trophy for the first time to Europe.
Boat type: Trimaran built of carbon composite materials
Builder: Core Builders in Anacortes, Washington
Sponsor: Golden Gate Yacht Club
Overall Length: 30 metres
Waterline Length: 27 metres
Mast height: 58 metres
Beam: 27 metres
Building time: 150,000 hours
Boat type: Catamaran of carbon composite construction
Builder: Alinghi-Décision in Villeneuve, canton Vaud
Sponsor: Société Nautique de Genève
Overall length: 27 metres
Waterline length: 27 metres
Mast height: 50 metres
Beam: 25 metres
Building time: More than 100,000 hours