Reigning horse of the year Gentildonna became the first back-to-back winner of the Japan Cup with a historic photo-finish victory over Denim and Ruby on Sunday at Tokyo Racecourse.

The 4-year-old Gentildonna, in her first partnership with English jockey Ryan Moore and who hadn't won yet in three previous starts this season, was declared the winner by a nose in Japan's richest race with a purse of ¥521 million — ¥250 million of it going to the champion.

Her time on firm going was 2 minutes, 26.1 seconds over 2,400 meters in an unexpectedly slow race paced by third choice Eishin Flash, who fizzled to 10th. Second pick and four-time Grade 1 champion Gold Ship sunk to a shocking 15th in a field of 17, and 11th-favorite Tosen Jordan claimed third a neck behind Denim and Ruby.