The horse and trainer both boasted pedigrees to be Classic winners, but Fancy Blue's win in the Prix de Diane at Chantilly was still an extraordinary feat for rookie trainer Donnacha O'Brien. 

O'Brien has saddled three winners in Ireland since surrendering an unwinnable battle with the scales and taking out his training licence at the start of the year, but the daughter of the late, great Japanese sire Deep Impact catapulted him into the big time by edging out Jessica Harrington's Alpine Star and his father Aidan's Peaceful in the French Oaks. 

Fancy Blue found only Peaceful too good in the Irish 1,000 Guineas three weeks ago, but that form was reversed as Pierre-Charles Boudot's mount prevailed by a short neck from Harrington's representative in a thrilling finish.

"It was nail-biting stuff, she could have won and she could have been fourth in the last few strides," her trainer told RTÉ Sport. 

"But she's s tough filly and she stuck her head out and she stayed the trip well, so thank God we ended up on the right side of the photo finish." 

A dual champion jockey, O'Brien was confident beforehand, but this looked a top-notch renewal of the race. 

"I thought she had a good chance," he said.

"Obviously, it's a very hot race. It possibly had more depth than even Epsom, bar the winner. 

"I thought she'd run well. You can never be sure that they're going to win a race like that, but she was in great form and I was hoping for a good run."

Former players in most sports say that managing doesn't compare to the thrill of taking to the field of play as an active participant, but it's rather different for jockeys who make the transition to the training ranks. 

"Everyone says it, but it's true. So much more goes into it," the 21-year-old said of his new vocation.  

"When your riding them, you're getting up on the back of them and when you get off them it's someone else's problem. 

"But when you're training them, you're seeing them every day, you're forming a bond with them and a relationship, so definitely a lot more work goes into training." 

O'Brien hopes he might have another star on his hands in the shape of Southern Cape, who is a daughter of Galileo and Group One-winning juvenile Tiggy Wiggy. 

"I've a nice two-year-old called Southern Cape, who was second at Leopardstown in his first run," he added. 

"I think he runs at Gowran on Wednesday, so he should be hard to beat. I think he's a nice horse."