Fame And Glory justified odds-on favouritism to give Aidan O'Brien his fourth consecutive Irish Derby, and a record-breaking seventh success, as a very strong early pace set up a straightforward victory for the Investec Derby runner-up.
Ladbrokes reacted to the performance by halving the son of Montjeu to 6-1 from 12 for the L'Arc de Triomphe at Longchamp, while Victor Chandler also 6-1 from 8.
Talk before the race had been how Fame And Glory could expect a strong pace, something that didn't happen at Epsom, and pacemaker Rockhampton certainly ensured that this was the case, setting a brutal gallop from the off.
Golden Sword, who won the Chester Vase under a front-running ride from Colm O'Donoghue, employed the same tactic, and the pair sat a few lengths behind Rockhampton, with Mourayan third.
Johnny Murtagh, aboard the favourite was happy to wait in mid-division, with Seamie Heffernan on Masterofthehorse, who was bidding to become the first jockey to win the race three years in a row, just behind.
Inevitably the ferocious pace set by Rockhampton took it's toll, and turning for home he quickly emptied, leaving Golden Sword in front.
Few had got competitive to this point, but the one that did pick up was the one that mattered, as Murtagh and Fame And Glory started to reel in both Mourayan and Golden Sword.
It briefly looked as if O'Donoghue was going to be able to hold the challenge of the Ballydoyle first choice, but with a furlong left Murtagh swept to the front and pulled clear to win by five lengths.
Golden Sword did finish second, giving O'Brien a one-two in the race, while Mourayan also stayed on to take third.
O'Brien said: 'He's got a lot oftactical speed and was very quick to get into his stride.
'He's a great traveller and he's a classy horse.
'It was a great performance from Golden Sword. He improved from his run at Chester and has improved again from the Derby at Epsom.
'It's unbelievable to win this race again.
'When there is expectation, like there was today, it's always tense - but this is marvellous.'
He added: 'He was special last year, and came through his trials well this spring.
'Johnny was over the moon and he has won very snugly.
'Everyone knows the Curragh is straightforward track and there is nowhere to hide.
'He has improved with every run and came back very well.'
Winning jockey Murtagh said:' This is like our Royal Ascot and a great champion always wins it.
'It was agood, solid gallop all the way - he relaxed very well.
'It was hands and heels, a very easy win.
'I thought when I worked him earlier in the week he was going to do something like this.
'I rode Sinndar and Alamshar and they went on to better things, and this horse has a similar profile.
'He could be the horse for the Irish Champion Stakes (at Leopardstown) later in the year.'
Of a possible rematch with Epsom Derby winner Sea The Stars, Murtagh added: 'He is 1-0 up, but hopefully we'll lock horns later in the year - it will be great for racing.
'I knew coming here that this horse was going to be a different proposition altogether.
'He improved quite a bit from Epsom, and I don't care what turned up today - he would have been hard to beat.
'He has improved mentally, is much sharper and on the ball.
'I think he will be consistent from now until the end of the year.'