The brilliant Diamond Necklace (3f St Mark’s Basilica - Prudenzia, by Dansili) retained her unbeaten record in style with a sparkling fourth Group 1 victory in the Nassau Stakes at Goodwood on Thursday. Trained by Aidan O’Brien, the three-year-old has now won all six of her starts, including last year’s Group 1 Prix Marcel Boussac and then two French Classic victories this term in the Poule d'Essai des Pouliches and Prix de Diane. Ridden again by Ryan Moore, Diamond Necklace raced enthusiastically behind the leaders before making headway from two furlongs out. She travelled smoothly into the lead from the furlong marker and went comfortably clear to win by two and three-quarter lengths. Moore said: “That’s the best she’s felt, she’s improving with her racing. Aidan said she was up in her weight a bit today so she’s obviously thriving. “She’s classy, it was very easy really. She travelled smoothly and quickened up well, she’s a little bit idle in front still, but she’s a proper racing machine. “She gives you a classy feel, every time I’ve ridden her she’s travelled with loads of pace, loads of enthusiasm and she has a turn of foot; that’s what her father St Mark’s Basilica had, a real good turn of foot and that’s what’s evident with her.” O’Brien added: “She’s lovely and she’s progressing and she was heavier today, but Rachel [Richardson, work rider] was confident that was just strength she was building rather than just being heavy and it was the way she went through the line. “There’s a lot of people around her who help her and she’s a lovely filly. This was a mile and a quarter against older fillies and we didn’t know what was going to happen. We put in a lot of pace as we didn’t want a Mickey Mouse race and she has options now. “You can see her quality the way she travels through a race and Ryan was hoping they would lead him longer and he just had to go on as her stride was getting broken. She’s a great cruiser and she has a lot of quality and is progressing great so I’m over the moon.” Diamond Necklace was bred by Ecurie des Monceaux and Skymarc Farm.