Unbeaten St Mark’s Basilica filly Diamond Necklace went on her winning way overnight at Goodwood when taking on older mares for the first time in the Group I Nassau Stakes (1m2f).
With wins at her past two starts in the Group I Prix de Diane (2100m) (French Oaks) and Group I Poule d’Essai Des Pouliches (1600m) (French 1000 Guineas), the Aidan O’Brien trained filly was a short priced favourite to keep her record perfect.
The top lot at the 2025 Arqana Deauville August Yearling Sale when sold for €1.7million to MV Magnier, Diamond Necklace is a filly that has been in the spotlight for her whole life.
Given a perfect ride by Ryan Moore, Diamond Necklace made it look all too easy when striding clear to win by two and three quarter lengths over quality older mares Friendly Soul and See the Fire.
With six wins from six starts Diamond Necklace is the Euro version of Autumn Glow in being a sale -topping yearling with freakish ability and Ryan Moore has ridden her in all three of her G1 wins this year.
“It couldn't have been anymore straightforward, it was very easy. Diamond Necklace has improved. She was very impressive today. She just feels like a proper racing machine now, doing everything right, travelled, quickened, does what she has to do, I'm delighted with her,” he said.
“She's strong through the race, travels powerfully, travels with pace, turn of foot… and turn of foot is a good weapon to have. I think 10 [furlongs] is probably her optimum but with those classy horses, she does everything right so there's a chance she'd stay further, she'd have no trouble dropping back as well.”
Where to next for the superstar filly is yet to be decided.
Diamond Necklace runs for the Coolmore partners and was bred by Ecurie des Monceaux and Skymarc Farm. She is the half-sister to multiple Group I winners Magic Wand and Chiquita (dam of Group II winner Emily Dickinson), as well as Group III winner Philomene.
She is the ninth winner and third G1 winner from 10 foals to race from stakes-winning Dansili blue hen Prudenzia.

Diamond Necklace is the first G1 winner among six stakes-winners for St Mark’s Basilica, who is due back at Coolmore Australia at a fee of $38,500.
His first Australian runners are juveniles and include undefeated stakes-winning colt Artistopolos, stakes-placed West Coast and promising metro winners La Barrita, Gentle Touch and Apostle.










