Aidan O’Brien’s three-year-old filly Whirl proved too strong for her rivals when running out a strong winner of the Group 1 Pretty Polly Stakes at the Curragh.

Following an agonising defeat to stablemate Minnie Hauk in the Epsom Oaks earlier in the month, Aidan O'Brien's filly dropped back to a mile and a quarter to take on Andrew Balding's Kalpana, who was sent off the 5/6 market leader to get back to winnings ways following her reappearance third in the Tattersalls Gold Cup here.

It quickly became clear that the contest would develop into a match between the classy three and four-year-olds as both fillies eyeballed each other deep into the straight. It was at this point that Kalpana, who was giving away twelve pounds to her three-year-old rival, loomed up travelling best under Colin Keane.

However, Whirl wasn't in any mood to be denied and pulled out more under an all-action Ryan Moore, fighting on bravely down towards the rail before going on to score by a length and a half.

"She's very special," said O'Brien on Racing TV. "She's very tough. Ryan gave her a great ride; he spread the pace out evenly and got the fractions spot on. For a filly coming back from a mile and a half, when you're trying to outstay something, you're walking a very tight rope trying to do that, but he got it spot on."

It was a second success in three starts this season for the daughter of Wootton Bassett, who was bouncing back to winning ways having landed the Musidora Stakes in fine style at York in May.

O'Brien added: "She's one of those unusual fillies. She doesn't blow; there's not a bit of flesh on her body at all. She's all muscle and bone. She's got a quality head, lovely ears and is very genuine. She's got big lungs and doesn't blow.

"She's the ultimate racing machine really."

On future plans of the 13/8 winner, O'Brien, who was winning the contest for the sixth time, said: "She can go anywhere now this filly. She can come back here to the Oaks; she can go to the Nassau (at Goodwood).

"It was an unbelievable race to watch. Colin (Keane and Ryan) weren't giving each other an inch the whole way. They lined up all the way into the straight and lined up together.

"That's what you want to watch when you come racing. Two riders and horses like that lining up the whole length of the straight at the Curragh on good ground.

"It's very special and I think it's a race we'll remember for a long time."