The winner -- piloted by Örjan Kihlström -- was always prominent and produced the decisive thrust in the final straight to take the 500,000-euro ($684,000) winners cheque at odds of 10/1 and make up for his runners-up spot in the 2011 edition.
Up and Quick -- piloted by trotting legend Jean-Michel Bazire -- was second at 4/1 while Norwegian raider Yoko Boko was third at 20/1.
Bazire had led the whole way until the closing stages of the 93rd Prix d'Amerique, although Kihlström was on his shoulder almost throughout the race, but had nothing left in the tank when the driver nicknamed the 'Iceman' came to challenge.
Kihlström belied his nickname to throw his hands up in the air after crossing the line and waved his whip in celebration.
Trainer Stefan Hultmann was overcome with the emotion of the achievement.
"This has been a dream, I have achieved it but I can scarcely believe it.
"I am too emotional to say anything else for the moment," he gasped tearfully.
Bazire was gracious in defeat.
"Up and Quick produced a very good performance...one is obviously disappointed when you are second in the Prix d'Amerique, but all credit to the winner," said a mudcaked Bazire, who has won the great race twice.
Two-time winner Ready Cash looked as if he might regain the title he lost last year in what was his final appearance in the race, but having moved into fourth as the race reached the business end, he lost all hope when he galloped coming into the final straight.
"He isn't the same horse as he was, he was tired and he just didn't have the vim this year," said his driver Franck Nivard of the nine-year-old.