Beat Black powered to a four lengths win to record a huge upset in the 145th Tenno Sho Spring at Kyoto on Sunday.
Ridden by Syu Ishibashi, the Hitoshi Nakamura-trained Beat Black made a race-winning move in the 3200m Group One event with 800m to run, opening up a commanding lead on the field.
Tosen Jordan finished second with Win Variation another two lengths behind in third while the hot favourite Orfevre, Japan's Horse Of The Year and Triple Crown winner, failed to pick up and was a well beaten 11th.
Orfevre's trainer Yasutoshi Ikee, was unable to immediately assess the cause for the disappointment and admitted future plans including his entry for the Prix de l'Arc de Triomphe in Paris will have to be reviewed.
"I want to apologise that he couldn't run as well as the fans' expectation," Ikee said. "I am not sure what has happened."
Jockey Kenichi Ikezoe added: "He was swept off his feet on the ground. A few times his steps were unbalanced.
"I felt his footwork was not smooth and he was not his usual self."
Beat Black, the 14th favourite at odds of 159/1, made use of his pace and stamina to hold off a strong field that included five G1 winners.
He landed his first win in over a year and his first career Graded race title, covering the 3200m distance in just 0.4 seconds short of the record.
It was also a first G1 victory for jockey Syu Ishibashi who is in his tenth season since his debut in 2003.
Trainer Hitoshi Nakamura captured his third G1 title in more than 30 years of training. His first was in the 1984 Yushun Himba (Japanese Oaks) and his second 16 years ago in the Asahi Hai Sansai Stakes.
Tosen Jordan gave a terrific effort in his bid to claim both Tenno Sho titles after his win in the autumn equivalent and may be considered for a Melbourne Cup bid.
