Kirby joined Lambourn trainer Cox as a 15-year-old in 2005, and the pair have since enjoyed tremendous success – including at the top table with Lethal Force, Profitable, Harry’s Angel and Golden Horde.
Cox was thrilled to see Kirby etch his name on the roll of honour in Britain’s biggest Flat race on Saturday – on the Godolphin-owned colt for trainer Charlie Appleby.
“I’m absolutely over the moon for him. It was spectacular,” he said.
“We’ve had some amazing days, but it is very special to see him win a Derby – the pinnacle of the racing scene. It’s such a wonderful achievement.
“We go back a long way, and I’m absolutely elated by watching him yesterday. It’s well-deserved, and on top of everything else he’s a really nice fella. I was very proud of what he did.”
Kirby himself was on Sunday trying to come to terms with his amazing success on Adayar.
Still replying to countless messages and missed calls, the 32-year-old plans a couple of days off to fully take in what has been a rollercoaster week.
From looking forward to the ride on John Leeper, then losing out to Frankie Dettori only to be given a second chance to be aboard Adayar for Charlie Appleby at the expense of champion jockey Oisin Murphy and then to win the premier Classic, is quite a story.
“It’s unbelievable. A great day,” Kirby told Sky Sports Racing. “It’s something I’ll never forget. I’m a bit stuck for words – it’s only just kicking in, but it’s fantastic.
“The Derby is the ultimate test. It’s still sinking in. It was a great feeling. It’s something no one can take away from me. I’m really pleased.”
Kirby savoured the moment, because he does not expect to ride Adayar again – with William Buick, who rode Hurricane Lane into third place, and James Doyle, sixth on One Ruler, as Appleby’s two main jockeys.
“We all know William Buick is stable jockey, and James Doyle is the second, so good look to the boys,” he said.
“I doubt I will ever come across him again, because the boys will have him back. That’s their job.
“I’d like to say what two great lads they are. They were the first to greet me and congratulate me – two top jockeys and two top blokes as well.
“I’m still trying to reply to messages and get back to missed calls. I will get back to everybody – it’s been a manic few hours.”
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