Deirdre has come from off the pace to win the Nassau Stakes at Goodwood and record a historic success for Japanese trainer Mitsuru Hashida.
Settled back in the field by Oisin Murphy as Mehdaayih and Hermosa set a stiff gallop, the five-year-old was strong at the end of the 2000m.
Brought over to run at Royal Ascot, the mare was undone by soft ground in the Prince of Wales’s Stakes and her connections made the decision to keep her in Britain for another run.
Although sent out at 20-1, Deirdre had form against some of the best horses in the world, such as Almond Eye and Glorious Forever, and eventually ran out a clear-cut winner.
Frankie Dettori appeared to have stolen a march on the John Gosden-trained Mehdaayih, who looked set to provide the trainer and jockey combination with another Group One triumph.
Deep inside the final furlong, though, Dettori’s mount had no answer to Deirdre, who won going away by a length and a quarter.
“I’m just glad they have brought a horse here and it has performed, because I’ve been saying since I’ve come back from Japan how they regard their horses and it is fantastic they have won a top-level Group One here,” Murphy said.
“She is already a Group One winner, but it is nice to do it in England. I can’t tell you how pleased and thrilled I am for everyone connected.
“There was no pressure on me, so I rode how I felt from instinct.
“You can see she is an absolute queen. She is a big, masculine type of a horse and I’m not surprised she was able to carry the 60 kilos which is more than what she is used to.
“Hopefully we will see more of them coming now. She is by Harbinger, who we know very well – he was a world champion and this is a huge result.”
Seiko Hashida Yoshimura, racing manager to owner Toji Morita, said all they hoped was to see her do her best.
“This was a very big challenge here. We all could see she was trying hard at Royal Ascot despite the heavy rain,” he said.
“We were just hoping to see the best from her and that was today on this glorious sunny day. Everything was good.
“We are always believing in her, but the other horses in there were great, too. We had some good luck and all the people supporting us as well.
“We were not really sure if Deirdre would like the course, as it is undulating. I’m not sure what the plan is, we have to discuss that.
“I think many Japanese people will be more interested in racing here and hopefully we can have a good influence on racing.”