Aidan O'Brien now ranks alongside the legendary Vincent O'Brien after securing a record-equalling sixth Dubai Duty Free-sponsored Irish Derby at the Curragh courtesy of Frozen Fire.

Last year's winning jockey and Ballydoyle number two Seamie Heffernan produced the 16-1 chance with a storming run down the centre of the track to secure a two-length success.

By doing so he avoided a rough race to his inside, with Johnny Murtagh's mount Alessandro Volta swerving violently left in the closing stages - interfering with even-money favourite Tartan Bearer and Curtain Call.

Dermot Weld's Casual Conquest kept out of trouble to be second for Pat Smullen, with Alessandro Volta third and Epsom runner-up Tartan Bearer fourth.

No sooner after crossing the line, though, had the stewards called an inquiry and reversed the placings of Alessandro Volta and Tartan Bearer, with Curtain Call holding fifth.

Heffernan anchored the Dante runner-up well in arrears and started to cut through runners down the straight.

And the race was all but over when Frozen Fire - just 11th at Epsom - shot down the centre of the sun-kissed turf with a burst of speed that left his rivals toiling.

O'Brien, completing a hat-trick of Derby wins following Dylan Thomas in 2006 and Solider Of Fortune 12 months ago, said: "Frozen Fire was second in the Dante but got trapped back in the Derby.

"Mick (Kinane) came in and said he was very happy with him and that he was a very good horse.

"All we wanted was an even, strong gallop and this is great for everyone involved as there are so many people in the team who make this happen.

"All of ours have ran great races, but I think Alessandro Volta got stage-fright when he turned into the straight and he wouldn't have seen a crowd like that in front of him before.

"This is a very special race and is a full test over a mile and a half.

"The Curragh is probably the greatest racecourse in the world as it is a very fair track and really tests a horse over a mile and a half."

The race was robbed by an 11th-hour injury to Epsom hero New Approach, and O'Brien added: "I hope New Approach does come back but the pace at Epsom slowed at halfway.

"When we want our horses to run we want an even pace to make sure the best horse wins.

"If it isn't a strong pace then the best horse often does not win, and to have the best horses winning is important for our whole industry.

"It is a real privilege to be mentioned in the same sentence as Dr Vincent O'Brien."

Heffernan added: "I rode him to run well and it has happened for us.

"I was really happy when I rode him in his last piece of work. I tracked Pat Smullen during the race and he tracked the favourite. When there was trouble in front I pulled out and got a great run.

"I feel on top of the world winning back-to-back Irish Derbys."

Weld has been knocking on the door this term with second-place finishes in races like the Irish 1000 Guineas, French Derby, and Pretty Polly Stakes.

He said: "It is very frustrating - we have been second in five Group Ones now but man and beast have given their all.

"The horse is coming forward every day and we'll now look at the Irish Champion Stakes and the Arc."

Tartan Bearer failed to build on his Epsom run after suffering interference, and compounded a bad day for jockey Ryan Moore, who was fined 1,000 before racing for being aggressive towards Curragh security staff.

Trainer Sir Michael Stoute said: "We were carried halfway across the course and it certainly didn't help.

"He (Alessandro Volta) pushed on and on and on us, and it didn't help."

Curtain Call's jockey Fran Berry said: "Alessandro Volta took me out of the race there."

While losing connections rued their luck, winning owner Michael Tabor took centre stage to receive his trophy from Dubai Duty Free in their first year of sponsorship of the Classic.

Tabor said: "I don't recollect a better time to have all the winners at Royal Ascot and then to come here and win a Derby I suppose is the pinnacle."

Coolmore supremo John Magnier added: "We have got to pinch ourselves really.

"We also have to thank Dubai Duty Free for their generosity and commiserate with Jim Bolger after his horse was withdrawn - especially when they are involved in the sponsorship - but I am sure there will be great days ahead."