Fame And Glory continued Ballydoyle's great tradition in the Gold Cup at Royal Ascot.
Following in the hoofprints of his former stablemate Yeats, who famously won four Gold Cups, the five-year-old stayed every yard of the two-and-a-half-mile trip.
Jamie Spencer kicked on two furlongs out on Aidan O'Brien's 2009 Irish Derby winner, and the 11-8 favourite had plenty left to hold off Godolphin's Opinion Poll by three lengths, with Brigantin third.
Tastahil set out to make all of the running before the veteran Geordieland, who so often found Yeats his nemesis in this race, pulled himself to the front.
But unfortunately for his connections, Geordieland had soon shot his bolt and was pulled up.
Duncan was the first of the big guns to play his hand, with Askar Tau travelling sweetly for George Baker.
But Spencer had not moved until the field turned into the straight.
He used his class to pull well clear of the field before Mickael Barzalona brought Opinion Poll (16-1) from the rear of the field to pass all bar the impressive winner.
"It was a very easy, push-button ride," exclaimed Spencer.
"It was a great training performance."
O'Brien said: "I'm delighted for everybody and for Jamie, who gave him a great ride.
"Thanks to everybody for letting a horse with his class run in the Gold Cup.
"Very few mile-and-a-quarter Group One winners you see running run in a Gold Cup.
"When horses have so much class they can often stay - class makes them stay.
"It's the ultimate test of class when you go that extreme distance.
"I'm just very privileged to have him."
O'Brien continued: "The plan was after today to give him a break and train him for the Arc again, so we'll take one step at a time and do like we always did with Yeats and give him a run at the back-end.
"We'll give him a break now and hopefully give him a run before the Arc.
"The Gold Cup next year? Wouldn't it be marvellous."
Spencer added: "We didn't go very fast early and I was delighted when I saw Geordieland going around the field with a mile and a half to go to inject a bit of pace.
"My fellow wasn't keen, but because he has so much class he is used to going that bit quicker, so when Geordieland went on that made him more comfortable.
"Aidan's a great trainer and his first two races this season were all about bringing him on.
"Everybody was doubting him for the last few weeks, but we never had any doubts and I'm absolutely tickled pink."
Coolmore supremo John Magnier added: "It's a very special race and winning it, you get a very special buzz out of that.
"He had all the credentials in that he was a class horse, so it was just a matter of would he stay.
"If I said to the others I wanted to retire him, I know what the others would say - they wouldn't want to.
"If he's well and healthy, this is the place for him.
"He's a very consistent horse, there's no doubt about it, and unless we mess him up he could run up a sequence, but it's hard to keep horses sound.
"If Sea The Stars hadn't been there, this fellow would have been retired to stud as a Derby winner."
The Godolphin team were delighted with the performance of runner-up Opinion Poll.
"It was a great run. The horse loves soft ground, Mickael dropped him out and let him finish," said Godolphin racing manager Simon Crisford.
Holberg, Goldolphin's other runner, was not suited by the rain-softened going and was well beaten.
"Holberg didn't like the ground but there was nothing else for him before the Goodwood Cup," Crisford added