Dylan Thomas suffered his first defeat of the season when losing out an enthralling battle with Notnowcato in the Tattersalls Gold Cup at the Curragh.
Last year's Irish Derby winner looked as good as ever with two wins this spring, and lost little in defeat with his head reverse by Sir Michael Stoute's raider.
Dylan Thomas, the 1-2 favourite, moved up to challenge Notnowcato soon after swinging for home in the 10-furlong Group One event.
But Johnny Murtagh's mount was not for yielding and battled on nose-to-nose down the straight.
Stoute's 7-1 shot never faulted and, with the rail to help, the Juddmonte International winner pipped Aidan O'Brien's monster four-year-old on the line.
The Mick Channon-trained Youmzain was third over a distance two furlongs short of his best.
Connections of Notnowcato were predictably ebullient at the outcome.
Evelyn de Rothschild, representing his two sons, the horse's owners, Anthony and David, said: "It was a wonderful ride by a wonderful jockey.
"I wasn't sure how he'd go as he doesn't like to be in front but Johnny got him settled.
"Dylan Thomas came up to him and they had a battle and that was as good as it gets.
"He did beat Dylan Thomas at York last year and it's nice to see a horse as good as that.
"He's improving all the time and is now entered in the Prince Of Wales's (at Royal Ascot) and the Eclipse (at Sandown)."
O'Brien said: "He (Dylan Thomas) ran a great race. I'm not going to make any excuses. We'll take him home and see how he is but all the big races are open to him."
Youmzain is set for a step back up in trip at Royal Ascot after his third. Bruce Raymond, racing manager for owner Jaber Abdullah, said: "He doesn't like to be in front so we had to let him follow the others."
Coral quote the winner at 7-2 from 8s for the Prince Of Wales's, with Dylan Thomas their 11-4 favourite.