Gentildonna has become the first dual winner of the Japan Cup, holding out Denim And Ruby in a tight finish.
The Sei Ishizaka-trained mare was ridden on Sunday by English jockey Ryan Moore who took her to a clear lead in the straight and managed to keep her going to the line for a narrow win.
Both the winner and runner-up are daughters of 2006 Japan Cup winner Deep Impact.
"I was delighted to be given the opportunity to ride and she proved what a courageous filly she is," Moore told At The Races.
"She proved what a special filly she is.
"I just wanted to have a nice position, settle and ride a nice smooth race. Unfortunately it was not the prettiest as they went slow and it was tactical.
"I was in front a bit early but she showed her massive will to win.
"She's very special and it was a real privilege to ride. On a personal level, I wanted to win this race and I needed a filly as tough and genuine as her to do it."
Dunaden, winner of the 2011 Melbourne Cup, fared best of the European raiders, finishing fifth in the hands of Jamie Spencer.
The Ed Dunlop-trained Joshua Tree raced prominently in the early stages but faded out of it while the Willie Mullins-trained Simenon, fourth in this year's Melbourne Cup, was also back in the field.