Joseph O'Brien is sure Ruler Of The World can maintain his unbeaten record and hand his father, Aidan, an 11th Dubai Duty Free Irish Derby this evening.

O'Brien Sr has saddled Galileo (2001), High Chaparral (2002) and last year's hero Camelot to win Ireland's premier classic, with that trio all succeeding on the back of Epsom Derby glory.

Ruler Of The World, ridden by Ryan Moore at Epsom, bids to follow in their hoofprints at the Curragh, with Joseph getting back on board for the first time since he won a maiden in April.

O'Brien Jr, who claimed his first Irish Derby aboard Camelot a year ago, said: "He's an exciting horse. He's won three times from three runs and won very nicely the last day at Epsom, so we're looking forward to it.

"You'd be hoping he will improve for the experience of Epsom and the Curragh is a fair track and he's won there."

A horse switching stables after today's race is Patrick Prendergast's Sugar Boy, who was snapped up by owner Sheikh Mohammed Bin Khalifa Al Maktoum earlier this week.

The colt beat Libertarian and Epsom third Galileo Rock on his latest start at Sandown, and Prendergast is hoping his extra freshness will stand him in good stead. He said: "He's in good shape and we've had no problems.

"The rain dance I've been doing hasn't worked, but there's nothing we can do about that. If I had everything my own way, we'd have had a drop of rain. I'd have been more confident about his chances then.

"It's my first runner in the [Irish] Derby and, to be honest, I haven't got round to thinking about the fact it will be his last run for me. We're looking forward to the race, he's going there well."

Chris Hayes has partnered Sugar Boy on his last five starts and hopes to break his classic duck. The jockey said: "He's probably the freshest horse going into the race as the others have been to Epsom and elsewhere.

"He's been a great horse for me and I've only been beaten once on him. I really have a proper chance in this classic."