Arcadia, California — December 2025 — The golden light of a Santa Anita opening day often illuminates the birth of new stars, but the conclusion of the 2025 Grade 1 American Oaks felt more like a masterclass in professional poise and lightning-fast adaptability. In a dramatic turn of events that saw a last-minute jockey change and a bold tactical surge, Kazushi Kimura piloted the lightly raced Ambaya to a gritty victory, transforming a substitute mount into a career-defining Grade 1 score.
Partnering with the chestnut daughter of Ghostzapper, Kimura navigated a challenging 1 1/4-mile turf test that pushed the limits of both horse and rider. The win was not only a testament to Kimura’s status as a premier “big-game” pilot but also a crowning achievement for trainer Jonathan Thomas, who orchestrated a graded stakes double on one of the most prestigious days in the American racing calendar.
Kazushi Kimura Pilots Ambaya Sudden Opening: The Call to Duty
The story of the 2025 American Oaks was fundamentally altered in the seventh race of the afternoon. Antonio Fresu, the rider originally slated to pilot Ambaya, suffered an unfortunate foot injury when his mount, Anmer Hall, drifted into the rail. With Fresu sidelined and the final Grade 1 of the year looming, Jonathan Thomas was left with a championship-caliber filly and an empty saddle.
Enter Kazushi Kimura. The Japanese-born rider, already a multi-time champion at Woodbine and a rising force in Southern California, had completed his scheduled mounts for the day and was preparing to head home. Instead, he found himself in a high-stakes “cram course” in the Santa Anita paddock.
“I may have grilled him a bit,” Thomas later admitted with a smile. “I made him watch replays, then I talked to him for five minutes, shook his hand, and said, ‘The filly is training fantastic. She can win if you get a good trip.’ And he rode her beautiful.”
Kazushi Kimura Pilots Ambaya: A Test of Versatility and Grit
The American Oaks is unique in the late-season schedule, serving as the final Grade 1 opportunity for three-year-old fillies. It requires a rare blend of tactical speed and route-running stamina. While the European invader Atsila took the bulk of the public’s attention as the favorite, Ambaya entered the gate as a relatively unproven 9-1 longshot, still eligible for first-level allowance conditions.
While the opening phases of the race saw Ribbons take a commanding early lead with soft fractions of :23.55 and :48.30, Kimura settled Ambaya into a patient rhythm. Positioned fifth along the rail, he ignored the early scramble for position, trusting the filly’s natural gears. As the field turned for home, the competition reached a fever pitch.
“She always steps through from the gate, but today was actually smooth right out of the gate,” Kimura remarked. “I didn’t need to fight with her or send her too much. I was tracking Flavien [Prat, aboard stablemate Will Then], and when he decided to move to the outside, I got the extra room for myself.”
Kazushi Kimura Pilots Ambaya The Climb: A Seam of Gold
The 1 1/4-mile distance is a “marathon” for turf fillies, and as the leaders began to tire, the race became a test of “feel.” The favorite, Cliffs, appeared to have the race won in midstretch under Jose Ortiz, having struck the front with authority. However, Kimura was busy threading a needle.
Finding a narrow seam between rivals, Ambaya responded to Kimura’s left-handed urge with a devastating turn of foot. It was a masterclass in “catch-riding”—the ability to jump on a horse you’ve never ridden and immediately understand its rhythm. The pair collared Cliffs in the final fifty yards, pulling away to win by a half-length in a final time of 2:01.02.
Kazushi Kimura Pilots Ambaya A Legacy Continued for Augustin Stable
While Kimura’s skill was the catalyst, the victory added a layer of historical significance for the legendary Augustin Stable and owner George Strawbridge Jr. Ambaya is a homebred, out of the Distorted Humor mare Kundray, whom Thomas also trained. By securing the gold, Ambaya became the first Grade 1 winner Thomas has conditioned for the Strawbridge family.
The win was part of a larger dominance for the stable. Thomas saddled three runners in the Oaks, with Will Then finishing a gallant third to complete a 1-3 finish for the barn. “To win a race like this for Mr. Strawbridge, who has been such a pillar of the sport, is incredibly special,” Thomas said.
Implications for the Future
The 2025 Finals didn’t just crown a champion; they highlighted the depth of talent currently rising through the American ranks. Behind Ambaya, the runner-up Cliffs and third-place Will Then proved they belong in the upper echelon of the turf division heading into their four-year-old campaigns.
The day also marked a cultural milestone for Santa Anita. A collaboration with the Japanese franchise Umamusume: Pretty Derby helped draw the largest opening day crowd since 2016, creating an electric atmosphere that Kimura—a hero in his native Japan—clearly relished.
A Defining Moment for Kazushi Kimura
For Kazushi Kimura, the 2025 American Oaks was the perfect “final bow” to a breakout year in California. By transforming a last-minute substitute ride into a Grade 1 triumph, he demonstrated the exact qualities that define a world-class athlete: technical excellence, mental toughness, and an intuitive connection with the horse.
As the sun set over Arcadia, it was clear that “The Kimura Method”—a blend of international experience and raw, adaptable talent—had set a new benchmark for future contenders at the Great Race Place.
| Position | Horse | Jockey | Trainer | Odds |
| 1st | Ambaya | Kazushi Kimura | Jonathan Thomas | 9-1 |
| 2nd | Cliffs | Jose Ortiz | Cherie DeVaux | 5-2 (Fav) |
| 3rd | Will Then | Flavien Prat | Jonathan Thomas | 7-2 |
This video provides an in-depth look at Kazushi Kimura’s remarkable rise from Japan to becoming a champion jockey in North America, offering context to the skill and preparation he brings to major races like the American Oaks.
Would you like me to look into the next scheduled starts for Ambaya and the rest of the American Oaks top finishers?
