The win of Trelawney Stud's Galileo mare Igraine (GER) in Saturday's Listed Caloundra Cup proved little more than an appetizer for what the great Coolmore stallion achieved a little later in Ireland.
For the second time in his storied career, Galileo (image Mark Smith) supplied a 1-2-3 finish in the Irish Derby but there were few punters cheering.
Two years ago, Padraig Beggy landed the Epsom Derby on O'Brien's 40-1 chance Wings Of Eagles then just as quickly faded into relative obscurity.
Resurrected to partner the stable's 33/1 chance Sovereign, Baggy took off and never looked back leaving the Epsom Derby hero Anthony Van Dyck six lengths in his wake with Norway a further two and a quarter lengths back in third.
It was just the second win from nine starts for Sovereign whose only win came on a heavy track ay Galway at two and at his most recent starts beat just three runner home as a 50/1 shot at Epsom.
O'Brien trained five of the eight starters.
"They were all there and they were all trying their best," O'Brien told Sporting Life.
"It was all very straightforward. Everyone knew Padraig was going to lead and Seamus (Heffernan, on Norway) was going to follow him.
"The race maybe unfolded a little bit unusually. What happened was that Donnacha's (O'Brien, on Broome) horse missed the break, he came out very slow and everyone might have expected him to fill the third position.
"Then Kevin (Manning, on Guaranteed) decided to take up that position. The lads had a nice lead, but they were still close enough. Padraig set perfect fractions, increased it from halfway and he wasn't for stopping.
"It was going to be a solid race. It was going to be a full mile and half and this track lends itself to that.
"They have to get the trip. This place is very uncomplicated and there is nowhere to hide out there.
"This horse had a very good run last year when Donnacha rode him in the Beresford ahead of Japan.
"He won his maiden by 10 lengths in Galway before that and it was always there. He's a Galileo and when they start galloping they usually don't stop.
"He could go to the King George or go to the Grand Prix de Paris in France and then could have a break and go to the Leger."
Galileo sired the trifecta in the Irish Derby after Australia defeated Kingfisher and Orchestra in 2014.
The victory of Sovereign will certainly be welcomed by Yulong Investments who purchased his sister You Only You through BBA Ireland for 240,000gns at last year's Tattersalls December Mares Sale.
They are out of the Danehill Dancer mare Devoted To You who was runner-up in the Group II Leopardstown Debutante Stakes, Group II Curragh Park Express Stakes and Group III Leopardstown Trigo Stakes.
Devoted To You is a daughter of the unraced Alleged mare Alleged Devotion whose nine winners include the stakes winners April Starlight, Humble Eight, Royal Devotion and Thady Quill.
Alleged Devotion is a half-sister to the mighty mare Balanchine who won the Irish Derby in 1994. She also produced the Sun Chariot Stakes winner Red Slippers who is the dam of the French Oaks winner West Wind and Easter Joy who is the dam of Helmet's dual Dubai World Cup hero Thunder Snow.