Jim Bolger’s juvenile had managed only ninth of 10 in this month’s Tyros Stakes at Leopardstown, having previously looked a youngster going places when he beat the well-regarded Wembley in a maiden over this course and distance.

The return to the Curragh did the trick, as Mac Swiney belied his starting price of 28-1 to pounce late as both he and 4-5 favourite Cadillac surged past Ontario on either side of the long-time leader.

Mac Swiney showed just the best turn of foot to beat Jessica Harrington’s Cadillac by half a length, with the same distance back to Ontario in fourth.

He was winning a race which has been dominated by Aidan O’Brien since Bolger and Manning last won the Group Two affair five years ago.

The same trainer-and-jockey partnership were also on the mark with Mac Swiney’s sire, and subsequent Epsom Derby winner New Approach, back in 2007.

Bolger’s daughter, Una Manning, wife of the winning jockey, said: “We’re delighted with that run.

“He did it well on (soft) ground he wouldn’t really appreciate.”

A return to the Curragh and move up to Group One level is now in the offing, with connections hoping Mac Swiney – who was given a 40-1 quote by Paddy Power for Epsom – can continue to follow his sire’s path.

Manning added: “The plan now is to go for the National Stakes. When he won here the last time (dad) thought he was his Derby horse.

“We’re very pleased with him, he was very good. It seemed to be a strong race today.

“Hopefully we can get a good result in the National Stakes now, and go from there.”

In other two-year-old action to note, High Definition led home a promising one-two for O’Brien in the Irish Stallion Farms EBF Maiden.

Wordsworth – a full-brother to the stable’s top-class stayer Kew Gardens – was sent off the 5-2 favourite for the mile contest and looked like obliging after getting a gap to overhaul Mcpherson.

But High Definition (7-1) stayed on relentlessly from the rear under Wayne Lordan to prevail by three-quarters of a length.

The winner earned an introductory quote of 33-1 from Betfair for the Derby, and Lordan said: “He won quite well and is a lovely big horse.

“He was a little raw early. Through the middle of the race they didn’t quicken away from me and I was getting into a nice rhythm. He finished out comfortably.

“He’s a lovely colt and he’s going to be a lovely horse next year going a trip.”

Fifth last time out in the Phoenix Stakes, the O’Brien-trained St Mark’s Basilica got off the mark at the third time of asking as he justified odds of 4-7 in the six-furlong Irish Stallion Farms Maiden, denying Loch Lein by a length and a quarter.

Winning rider Seamie Heffernan said: “He had a very good run in a Group One and was basically a steering job.

“I’d say there is a high chance that he’s going to get further than six furlongs. I liked him.”