Windsor Park Stud's graduate So You Think registered a tenth success at the highest level as he denied Carlton House a fairytale win for the Queen at Royal Ascot in her Diamond Jubilee year.
The two-and-a-quarter-length win took So You Think through the £5 million career earnings mark, completed a double on the afternoon for trainer Aidan O'Brien and provided his son Joseph with a first win at Royal Ascot.
Sent off the well-backed 4-5 favourite, So You Think managed to go one place better in the race than last year when he was beaten at 4-11.
Carlton House had looked momentarily like he was going to post a popular win as he came with a challenge under Ryan Moore up the rail but he was never able to head So You Think and finished just a half-length in front of the third-placed Farhh.
O'Brien's training of So You Think had come under fire from his previous trainer Bart Cummings and the media in Australia and in the immediate aftermath of the race O'Brien said he felt he had got the horse wrong when he first joined him.
"It took me a year and a half to learn how to train him," he said. "I went back and listened to what everybody was saying to do with him. I was probably overworking him, galloping the speed out of him, and I suppose I set off on the wrong leg with him."
O'Brien junior always had his mount close up to his pacemaking stablemate Robin Hood and he said: "Once my horse got to see him [Carlton House] on the inside he was never going to get beaten."
So You Think could have his final start in next month's Coral-Eclipse before taking up stud duties in Australia and his trainer added: "We felt we had him in a place like never before. We knew we only had today and maybe Sandown to get it back. The boys will talk about it and we will give our input but we are just delighted to get him back to where Bart had him."
Sir Michael Stoute had told reporters after the race that he had known Carlton House was up against a very good horse in So You Think, while Saeed Bin Suroor was pleased with the effort of Farhh who was making a massive step up in grade.
"He ran well and I'm very happy. It was a big race to finish third in the Prince of Wales's and he's improved a lot. He hasn't always been the soundest - nothing major - so we'll see how he comes out of the race.
"We'll look at the King George, but we'll keep our options open. I'm confident he's a Group 1 horse over a mile and a quarter to a mile and a half."