Fame And Glory showed class and stamina to win the Gold Cup at Ascot.
The former Irish Derby winner, trained in Ireland by Aidan O'Brien, justified a late gamble with a convincing triumph in the two-and-a-half mile race.
Running for the first time over more than a mile and three quarters, the 11-8 favourite prevailed by three lengths under Jamie Spencer.
Opinion Poll was second with fellow 16-1 shot Brigantin a further four-and-a-half lengths back in third.
The final race of the day then produced one of the stories of the meeting so far, when Brown Panther, bred by former England striker Michael Owen, won the King George V Stakes.
The 4-1 joint-favourite was a second winner of the week for both trainer Tom Dascombe and jockey Richard Kingscote - the key figures at the Cheshire yard owned by Owen.
And this time the Manchester United footballer had to wipe away tears before facing the BBC cameras.
"Owning a horse that wins at Ascot is one thing, but breeding one, this is different and it doesn't get any better," said Owen.
"We had a winner yesterday and it's been quite special. It was a time for patience last year and that patience has paid off. I'm delighted to have such a nice horse. There's not many better feelings than this."
O'Brien's success in the day's feature followed four consecutive successes between 2006 and 2009 with the brilliant Yeats in the same race.
A new statue of the retired Yeats was unveiled by the Queen in the Ascot parade ring two days before the Ballydoyle trainer sent out another of his stars in the feature race.
Fame And Glory was a relatively uneasy 5-2 shot on the morning of the race as rain came down and uncertainty surrounded his ability to see out the gruelling trip.
But, in the minutes before the off, punters backed him as if defeat was out of the question - and he delivered in style.
It was a fifth Group One victory for the five-year-old, who was runner-up in the 2009 Epsom Derby to the great Sea The Stars.
O'Brien was claiming his 33rd Royal Ascot triumph to put him fourth among current trainers at the famous meeting.
Bookmakers reacted by installing Fame And Glory as a 3-1 chance to win the Gold Cup again in 2012, with four wins rated at 66-1 and a new record of five 200-1.
"I'm delighted for everybody, delighted for Jamie [Spencer], who gave him a great ride," said trainer O'Brien.
"Very few mile-and-a-quarter Group 1 winners run in the Gold Cup. [But] when horses have so much class they can often stay.
"Class makes them stay and it's the ultimate test when you go that extreme distance. Class is very hard to replace and Jamie was very confident and gave him an unbelievable ride."
Spencer added: "We didn't go very fast early, so I was delighted when Geordieland injected a little bit of pace.
"My fella wasn't keen, he wanted that injection of pace to make it into a race. It was a very easy push-button ride for me."
Earlier, Ribblesdale Stakes favourite Banimpire won by a short head after a titanic battle with Field of Miracles.
Field of Miracles looked all set to give Richard Hughes his fourth win of the meeting before being overhauled by Kevin Manning on Banimpire, with Dorcas Lane coming third.
Banimpire's trainer Jim Bolger said of the winner: "All she does is eat and sleep, she only exerts herself on the racecourse."
Bapak Chinta had taken the opening race of the day after holding off a clutch of rivals to power home in the Norfolk Stakes.
The pre-race favourite had drifted out to 6-1 but rewarded those who kept the faith by making the running from three out in the five-furlong dash, leaving Boomerang Bob and Crown Dependency trailing in his wake.
"It's brilliant [to have a first Royal Ascot winner]," said winning jockey Phillip Makin. "I've not sat on a two-year-old as sharp as him."
Sagramor came home first in the Britannia Handicap, ahead of Cai Shen, The Tichborne and Belgian Bill.
And in the day's penultimate race, 20-1 shot Pisco Sour ran clear down the straight to win the Tercentenary Stakes and make it a quick one-two for Hughie Morrison, who also trains Sagramor.