Aidan O'Brien knows more than enough about this Classic, as it was an unprecedented third victory in a row for the Irish trainer, and the pronouncement he made last autumn of the chestnut being perhaps the best horse to have been in his care has followed him around ever since.
Having a Derby-winning sire (Galileo) and an Oaks-winning mother in Ouija Board equipped the 11-8 favourite with the genes to excel at this idiosyncratic venue, but with Kingston Hill breathing down his neck right the way to the line, this was not a fait accompli.
The Qipco 2000 Guineas once again proved the pivotal piece of form, as it has thrown up the Irish Guineas victor in Kingman, French Derby hero The Grey Gatsby and now Australia, who finished an encouraging third over a mile at Newmarket having been one of many at O'Brien's Ballydoyle stable to have suffered from ill health in the early spring.
Our Channel and Australia's stablemate Kingfisher managed to supervise the front-running until well past Tattenham Corner, with Joseph O'Brien moving into a position to challenge with just over two furlongs remaining. From that point, it looked as if there could only be two possible winners. Second-favourite Kingston Hill, who had been settled closer to the lead by Andrea Atzeni, returned a mighty effort and while he was unable to stop Australia when he went past at the distance, he held manfully on to his coat-tails and was beaten by only a length-and-a-quarter.
Australia has achieved his greatest mission, and O'Brien senior was asked to explain why he rated him so highly, having trained such other world-beaters as Galileo himself, Giant's Causeway and High Chaparral.
"It's very simple, it's pace," he said. "He has terrible pace, terrible class, he's able to go from A to B so easy, which is so unique for a horse that's bred the way he is.
"Everyone knew every sinew in his body was going to be tested here, he was going to have to quicken and have to travel. What makes him different is his natural pace."
Reflecting on his achievement, never before achieved in 235 years of the race, and his fifth Derby overall, he said: "It's special but we are lucky to have such well-bred horses to handle, that's the reality of it. When you have Galileos bred the way they are, everything is possible.
"We thought this horse was very special from the first day he worked.
"His work was excellent and we saw what he did in the Guineas. We couldn't expect him to get a mile-and-a-half even with his pedigree as he's shown himself to be so speedy, but Joseph was going to ride him safe and confidently and that's what he did."
O'Brien junior said: "We've made no secret about this horse and I knew I was on the best one, so I just wanted to give him a chance to do himself justice.
"I was going very easy coming down the hill, nearly a shade too easy and I got nudged out coming to the bend. I got there a mile too soon but I had to stay going where I was getting. He was idling probably when I got to the front, I felt I was getting there to beat [Kingston Hill] well, and he's just given a little look. As a two-year-old he was lazy, but he's push-button now.
"Horses don't come easier to ride than this fellow - he's the best."
While the winner ran in the purple colours of Derrick Smith, part of the Coolmore triumvirate, Kingston Hill is owned by his son, Paul, who said: "I'm delighted, dad can pick up the bill tonight!
"I always knew what they thought of Australia, but our horse has run a great race."
Cirrus Des Aigles claimed his sixth Group One success in the Investec Coronation Cup. Already the conqueror of Arc heroine Treve, the 10-11 favourite was ridden confidently by Christophe Soumillon and comfortably held his compatriot Flintshire by two lengths.