Aidan O’Brien’s unbeaten Diamond Necklace faces her toughest test to date when she takes on her elders for the first time in the Qatar Nassau Stakes at Goodwood on Thursday.

A Group 1 winner in France as a juvenile, this year she has successfully hopped back across the Channel a couple of times, first to win the French Guineas and then when handling the step up to 10 furlongs with aplomb in the French Oaks.

Life is now likely to get a little harder for the daughter of St Mark’s Basilica, who is a half-sister to Magic Wand and Chicquita, as she faces not only high-class older fillies but also encounters Goodwood’s unique twists and turns for the first time.

“I think she’ll be fine,” said O’Brien. “She’s well-balanced. She’s a medium-sized filly with a good stride.

“She’s been around Longchamp and Chantilly, both right-handed tracks, so I don’t think that should be a problem.

“She looks very good at the moment. She looks very special. Everything she’s been asked to do, she’s done very easily and very comfortably.

“She is obviously in that ‘could be anything’ category. She looks really special at the moment and we’re very excited to have her.”

Taking her on is Friendly Soul, who has a claim to being the most unlucky horse of the season to date.

First time out at Haydock it was John and Thady Gosden’s five-year-old who discovered the hole in the ground when it looked as if she was about to win a Listed race, and then at Royal Ascot Oisin Murphy repeatedly found his path blocked as he searched for a run before flashing home for third behind Blue Bolt.

“She ran a good race at Ascot, but just didn’t have a smooth trip round and when you get stuck on that rail it’s hard to get out of trouble there,” said Thady Gosden.

“She’s come out of the race well and a mile and a quarter will suit her well. She’s won the Prix de l’Opera over a mile and a quarter before and she will have the speed for the track.

“She’s proven at this level and seems in very good order with herself at home. I’m sure she will run a very nice race.”

See The Fire has been placed in the race twice before. She was second to Opera Singer two years ago before finishing third behind Whirl last season.

Having won the Middleton Stakes at York for a second time in May, she then lost little in defeat when sixth behind some of the best in the world in the Prince of Wales’s Stakes at Ascot and is looking to provide the very much in-form Andrew Balding with another Group 1 success.

“I’d hope she will run very well, but it’s never easy taking on Aidan and he’s got the better of us in the race the last two years,” said Balding, fresh from King George glory with Kalpana.

“She’s in good form and she enjoys the track, which I think helps – on fast ground there a couple of years ago she really looked good.”