“I'd say she'll probably start in the Guineas next year”

Aidan O'Brien looks to have yet another top-class juvenile filly on his hands after Diamond Necklace (St Mark's Basilica) took her record to three wins from as many starts with a comfortable victory in the 1600m opening Qatar Prix Marcel Boussac (Gr.1).

The daughter of French Classic hero St Mark's Basilica arrived at Longchamp looking to keep her unbeaten record intact having followed up a faultless debut success at Dundalk with a smooth win in the Ingabelle Stakes (Listed) at the Curragh.

Nicely positioned in midfield under Christophe Soumillon, Diamond Neckless swung widest off the bend coming into the straight before setting off the chase down her fellow unbeaten rival Green Spirit.

It quickly became clear that they were the two that were going to battle out the finish and although the handily positioned Green Spirit find plenty off the front end under Maxime Guyon, she always looked susceptible to the finishing kick of Diamond Neckless, who drew alongside in the final 100m before going on to score by a length.

Narissa finished back in third, with Esna emerging with plenty of credit a further neck behind in fourth.

O'Brien, who has previously landed the opening Group 1 prize on Arc day with the likes of Ballydoyle, Found and Opera Singer, said: "These St Marks Basilica's have been getting better.

"He didn't win his Group race until the Dewhurst, and that's two weeks to go, but he was like that himself.

"He came out at three, and we saw what he did at three. They're very like that.

"We thought she was a bit babyish to come here, but Christophe (Soumillon) rode her at Leopardstown, and he said, leave her. We'll do it and then leave her alone for the year.

"We're very happy really. I'd say she'll probably start in the Guineas next year like we do with them all and take it from there. She's not short of speed. They're obviously all very like him."

A wowed Christophe Soumillon added: "She's amazing. I was very confident; she was my best ride of the weekend.

"The last time, she gave me a great sensation and was so relaxed going to the start and professional. She picked up so easily, and it was just hands and heels only. She will be a great filly for next year; she is going to do something great."