CLASSIC heroines Laurens and Sea Of Class will do battle in a mouthwatering renewal of the Darley Yorkshire Oaks on Thursday.

Having rounded off her juvenile campaign with a Group One success in the Fillies' Mile, the Karl Burke-trained Laurens finished second in the 1000 Guineas in May before claiming further top-level honours across the Channel in the Prix Saint-Alary and the Prix de Diane (French Oaks).

She steps up to a mile and a half to take on her elders for the first time on the Knavesmire, where she will once again be ridden by PJ McDonald.

McDonald made his name originally as a National Hunt jockey, but has taken his career to another level since switching to the Flat and fully expects Laurens to relish the longer distance.

Speaking ahead of what is another leg of the Qipco British Champions Series, he said: "You could go through your whole career and not find a horse like her. She's a once-in-a-lifetime filly.

"It's been a privilege to be involved with her, but the exciting and scary thing is that she's still improving, still getting stronger.

"I'm itching to ride her over a mile and a half because if she improves again for stepping up in trip then she could be an absolute monster.

"We always thought she would have no problem staying and I have no doubts in my mind, whatsoever, after the way she won the French Oaks.

"Most of them have all run over the distance, whereas my filly is still unexposed over that trip. None of us have a crystal ball and she might not get home, but I would be shocked if that was the case. The dam's side of her pedigree is all stamina."

Sea Of Class was unraced as a two-year-old, but has appeared intent on making up for last time this season, winning three of her four starts for William Haggas including a thrilling triumph in last month's Irish Oaks at the Curragh.

The Sea The Stars filly was given an ice-cool ride that day by James Doyle, who was content to bide his time at the rear of the field before making his move.

Assessing tactics for this latest test, he said: "I don't think we have to sit last, that was the way it panned out at the Curragh. They can get away on the front end at York, so I will speak to William and we will come up with a plan."

Reflecting on the Curragh victory, Doyle added: "I always thought I was going to get there. I was a little bit conscious of the (mile and a half) distance, but she's got a devastating turn of foot, so I don't think she's one to be in the mix early.

"She likes to relax, chill out out in the early part of a race and then come home really good.

"She showed what she could in Ireland and, being very lightly raced, I'll be amazed if she has not improved since. She's unexposed and if she keeps improving could be anything."

Laurens and Sea Of Class are two of five three-year-olds in an eight-strong field, with Aidan O'Brien responsible for the other three.

Forever Together won the Investec Oaks at Epsom before being touched off by Sea Of Class on home soil. Bye Bye Baby and Magic Wand need to raise their game after finishing fourth and fifth respectively in the Curragh Classic.

The Ballydoyle trio are joined on the trip from Ireland by Dermot Weld's Eziyra, who rises in class following an impressive belated reappearance in the Ballyroan Stakes at Leopardstown a fortnight ago.

John Gosden's Coronet - who was runner-up to esteemed stablemate Enable in last year's renewal - and Horseplay from Andrew Balding's yard complete the stellar field.