Heavy favourite Australia (1/10) landed the Dubai Duty Free Irish Derby at The Curragh to add to his Epsom Derby success earlier this month and give trainer Aidan O'Brien an amazing 11th triumph in the Irish showpiece.
Winner of the Investec Derby at Epsom on his previous start, the colt followed in the hoofprints of his sire, Galileo, who took this prize in 2001 and his dam, Ouija Board, the Irish Oaks winner in 2004.
Joseph O'Brien, riding his second Irish Derby winner, sat in third place as stablemates Kingfisher and Orchestra made the running.
He made his move on Australia in the straight before leading a furlong out and going on to score as he liked.
The 1-8 favourite was eased down close home, while Kingfisher (25-1) was second and Orchestra third as the O'Brien team filled the first three places.
Australia was sent off at a highly prohibitive price after the race was reduced to just five runners with the late defections of Epsom runner-up Kingston Hill and the winner's stablemate, Geoffrey Chaucer.
However, the expectant crowd got the result they had hoped for as the Ballydoyle inmate completed the Derby double in championship style.
"The environment here is so unique and special and I think there are many people in China that would love to come if they knew of this special quality here" - Co-owner Teo Ah Khing
Australia has been rated a special horse from his early days, as co-owner John Magnier explained.
He said: "It was very easy to spot Australia at the sales, being by Galileo out of such a famous mare.
"It was a no-brainer once he looked the part and, medically, he was OK.
"I was confident before the Irish Derby because I'd been listening to Aidan since he (Australia) was a two-year-old.
"You know Aidan doesn't do that (describe Australia as the best horse he has trained) in an arrogant way.
"He genuinely believes that and he just wanted to share it with people.
"Some days there would be Press people down there (in Ballydoyle) for three and four hours at a time and I guess you wind up, you have to say something, so if he believed he was good, why not say it?
"It adds a bit of excitement and, of course, it puts 12st 7lb on the horse as it's a stick to beat yourself."
Joseph O'Brien believes Australia could have even more to offer over a shorter trip.
He said: "This is a very special horse, he was an armchair ride. He has a massive engine and we still haven't seen the best of this horse.
"I'd love to ride him at a mile and a quarter - I think that's going to be his thing on fast ground. His attitude and his pace sets him apart from the others.
"He's a great mover and he's so well balanced. When I walked him down to the barn and came back before the race for the parade, he'd have stayed asleep.
"The Irish Derby is one of the races you watch growing up. To be riding in the race is a dream and to win it is unbelievable."
Teo Ah Khing, fellow co-owner of Australia, said: "This is one of the most special horses we ever could find in the world.
"The environment here is so unique and special and I think there are many people in China that would love to come if they knew of this special quality here."