Orfevre (3-5 favourite) signed off from his racing career in style when he sailed home in the Grade One Arima Kinen at a packed Nakayama racecourse.
Runner-up in consecutive renewals of the Prix de l'Arc de Triomphe at Longchamp, the Yasutoshi Ikee-trained five-year-old will now retire to stud after winning 11 of his 19 races.
Orfevre's eight-length verdict over Win Variation in the twelve and a half furlongs contest was achieved in front of an extraordinary 124,782 racegoers.
Ryan Moore was aboard Gold Ship, but the partnership could finish only third, another length and a half in arrears.
It was Orfevre's second victory in the Arima Kinen after he struck as a three-year-old in 2011 - a year in which he also claimed the Japanese Triple Crown.
Jockey Kenichi Ikezoe said: "I tried to focus on how to settle the horse and to keep him in good rhythm, instead of where to position him.
"He was a bit keen to go but I kept him reserved behind Gold Ship hoping he would stay settled.
"It might have been a bit earlier to make our bid than usual, but he responded so well.
"I was confident making the last turn that no one would ever be able to catch him.
"He is definitely the strongest horse in the world."