Serpentine, trained by Aidan O’Brien and ridden by Emmet McNamara, created a huge shock as he made all for a 25/1 success in the Investec Derby at Epsom.
O'Brien saddled six in the premier Classic - but it was McNamara's mount who prevailed, having only shed his maiden tag at the Curragh last Saturday.
Serpentine appeared to be employed to help set the pace at the head of affairs, but the field allowed him to build up a huge lead and he was still well clear at Tattenham Corner, with Khalifa Sat and fellow O'Brien runner Amhran Na Bhfiann sitting in second and third.
The main players were all trying to make their move in behind, but the winner had flown, coming home five and a half lengths clear, to give O'Brien a record eighth win in the race.
Khalifa Sat took second at 50-1 with Amrhan Na Bhfiann third at 66-1.
O'Brien said: "It's unbelievable really. He has some pedigree and we always thought he would stay well.
"Wayne (Lordan) won on him over a mile and a quarter at the Curragh last week and he galloped straight through the line. He went an even pace and Wayne said he couldn't pull him up.
"We were happy he wasn't going to stop and go an even pace. He wasn't going to come back. He's another home bred by Galileo. It's incredible really.
"He always had the Derby pedigree. He took a bit of time to come last year and just had the one run. Then this year he had his first run at the Curragh over a mile and a quarter and was hemmed in and couldn't get out. But he won very impressively last week. There was no doubt with his performance the last day he had to take chance.
"I'm absolutely delighted for Emmet. He gave him an incredible ride, so I'm over the moon.
"They all run on their merits and we give them the best instructions for each horse to win the race. He stayed well and there was no point waiting with him with no pace.
"We are always delighted if one of them wins."Earlier, Love made it a Classic double as she ran right away with the Investec Oaks.
Winner of the 1000 Guineas for Aidan O'Brien and Ryan Moore last month, Love was sent off the 11-10 favourite to follow up over 12 furlongs.
Love was ridden with restraint by Moore in the early stages, as stablemate Passion and outsider Tiempo Vuela set the early gallop, with the pair pulling well clear of the field until the home turn.
However, Love could be noted making her move around three furlongs out and while main market rival Frankly Darling tried to follow her, the winner had far too much pace.
She shot clear in the final quarter-mile to eventually come home nine lengths clear of fellow O'Brien runner Ennistymon, with Frankly Darling back in third for Frankie Dettori.
Moore told ITV Racing: "This filly is very special. She didn't stop at all. She actually got down to the rail and picked up again.
"She was very impressive - she's very good."
O'Brien said: "Delighted really. Everybody was very happy with her here.
"She's a home-bred, so we're delighted for the lads. They put so much into it, day in day out. It's unbelievable."