Diamond Necklace kept her unbeaten record intact and joined a list of all-time greats by winning the Prix de Diane at Chantilly on Sunday.

Trained by Aidan O'Brien, the odds-on favourite had to work very hard under Ryan Moore to get home a neck in front of 50/1 shot Pink Panthera. David Menuisier's Inis Mor was third.

In victory, Diamond Necklace was completing a remarkable treble, adding this classic to her success in the Poule d'Essai des Pouliches last month, and her Prix Marcel Boussac win last October. Zarkava completed the same treble in 2007-'08.

For Ryan Moore it was a first win in the race while the odds-on favourite was giving O’Brien a second following the success of Joan Of Arc in 2021.

Moore insisted he was always confident his filly would hold off the attentions of the strong-finishing Pink Panthera once he got Diamond Necklace to the front at the furlong marker.

“I never thought we were going to get beat. I think she does what she really needs to do. She is very straightforward and was very professional in everything she has done through the race,” he said.

“At the moment we don’t know what she can’t do as she’s answered every question she has ever been asked. She is so straightforward, a great mover and she has handled bad ground in the Guineas and good ground today.

“She was very comfortable on it and she might stay further, I suppose. But she has pace.”

Diamond Necklace was continuing Ballydoyle’s near total dominance in the three-year-old classics in England, Ireland and France with O’Brien training the winners of six of the 10 run so far.

Only Bow Echo, Rayif and Thundering On have denied him a clean sweep of the six Guineas, two Oaks and two Derbys run so far this campaign.

O’Brien said: “She’s a very good filly and Ryan gave her an unbelievable ride.

“We’re were happy through the race, it was evenly run, Ryan said he’d take his time as she quickens well and he was over the moon. She’s never run on ground that quick but he said it was no problem.

“She’s by St Mark’s Basilica and she’s very like her dad, she’s not big but quickens well and he didn’t want further than 10 furlongs so maybe she’ll be the same.

“At home in her work when she gets there she doesn’t do much, maybe she doesn’t have to go further. She’s very classy, the sky is the limit.

“She’s very similar to St Mark’s and like him, she’s stepped up from two to three.”

Bought for €1.7 million as a yearling at Arqana, Diamond Necklace is from the first crop of St Mark's Basilica, himself a dual French classic winner for Ballydoyle. The filly is out of Prudenzia (by Dansili), already the dam of Group 1 winners Magic Wand and Chicquita.