Lord North has taken out the showpiece Prince Of Wales's Stakes on day two of Royal Ascot in impressive fashion for trainer John Gosden.
The four-year-old, in his first appearance in Group One company, showed a blistering turn of foot under James Doyle to finish 3-3/4 lengths ahead of Addeybb.
Addeybb was having his first start since winning the Queen Elizabeth Stakes at Randwick in April.
Lord North could become a Royal Ascot regular after his stud career was curtailed last year, but Gosden believes it was a move that had to be taken so he could fulfil his potential.
“That decision was taken out my hands,” Gosden said.
“Testosterone is the most dangerous drug in the world and it was certainly driving him completely mad!
“Since he's been gelded he's a very content, still very playful horse, but he's not crazy like he used to be.
“We've always thought he was a very classy horse. It's taken a long time to get it out of him, but that has always been more to do with the mind than anything else.”
The Queen clocked up her 24th Royal Ascot winner when two-year-old Tactical justified his favourite's tag to win the 1000m Windsor Castle Stakes.
Doyle added to his earlier success on Lord North when he finished strongly to run down eventual third Muker with Yazaman running on late to snatch second.
Royal Emperor, whose dam is former top-class Australian winner Atlantic Jewel, took out the Group Three Hampton Court Stakes with Ryan Moore on board.
Moore nudged out First Receiver, ridden by Frankie Dettori and also owned by The Queen, with a perfectly-timed push for the line to hand O'Brien his second winner of the week.
One-time Classic hope Dark Vision won for the first time in nearly two years when claiming the Royal Hunt Cup.
The Mark Johnston-trained colt was bought by Godolphin after lifting the Group Two Vintage Stakes at Glorious Godwood in July 2018 but had been beaten in all his 13 subsequent races.
But under William Buick, he finally got his act back together as he came with a strong late run to win.
The opening race of the day saw top weight Sir Busker, a $12 shot, win the Silver Royal Hunt Cup Handicap.
Jim Crowley continued his outstanding start to the meeting, piloting Hukum to victory in the King George V Handicap Stakes.
The final race saw Roger Varian's Fujaira Prince become only the second winning favourite of the day when he claimed the Copper Horse Handicap.