Leading Light thwarted the Queen's 2013 victor Estimate and Mick Winters' gallant 40/1 shot Missunited in another epic edition of the Gold Cup to cap a memorable Ballydoyle double at Royal Ascot.
Aidan O'Brien's season has been a veritable rollercoaster so far, but Bracelet had dug deep to get him off the mark for the week under a determined drive from his son Joseph in the Group Two Ribblesdale Stakes 35 minutes earlier.
That change in fortune prompted a boost in confidence ahead of the week's marquee Group One, with the champion jockey duly declaring that the 2013 St Leger winner would be hard to beat if his stamina could stretch to two-and-a-half-miles.
The Montjeu four-year-old claimed this afternoon's Queen's Vase on his inaugural visit to this uniquely glamorous affair 12 months ago, but he is out of Dance Parade, which won the Queen Mary here over five furlongs as a juvenile in 1996.
Yesterday's affair was new territory, and Leading Light didn't shirk the issue when the gloves came off half-a-mile out.
O'Brien had enough horse to force Ryan Moore to switch the Michael Stoute-trained Estimate inside Missunited shortly after they began the final climb.
At that stage, Missunited still held the initiative that she seized under Jim Crowley from the off, and Winters' versatile Galway Hurdle winner refused to yield as her two more regally connected rivals loomed either side.
They slugged it out to the line, with Leading Light eventually emerging on top in an absorbing spectacle. Having not run since October, Estimate's neck reversal constituted a stellar turn.
She scraped home from Simenon in 2013, but this was arguably a career-best performance even in defeat. The same could accurately be said of the brave Missunited, whose dogged determination saw her denied just a short-head for second.
Indeed, each of the men responsible for saddling the first three excelled.
O'Brien has found it hard to establish any momentum all year, but victory for his 10/11 favourite here saw him become the most successful trainer in the history of the festival's oldest race, following his five previous wins with Yeats (2006-09) and Fame And Glory (2011).
Earlier in the month, he earned the distinction of becoming the first trainer to win the Derby three times in a row with mighty Australia.
The Wexford-born wizard had gone ominously close in the previous two marquee Group Ones this week, with Verrazano and Magician, so this was further proof his elite team is beginning to emerge from its slump.
"Your heart was in your mouth for that one," admitted O'Brien as the 10th Irish-trained Gold Cup winner stood spent in the hallowed circle.
"I think Joseph did very well. I am so lucky to have the horses I have and to work with the people I am working with."
In contrast to his father, this was 21-year-old Joseph's first Gold Cup triumph. As is ever the case on the big day, he proved more than equal to the task.
"If you win, it's always a good ride, there's no such thing as a bad winning ride," the brilliant rider said in an effort to deflect praise.
However, having initiated his 20/1 brace aboard the back-to-form Bracelet (10/1), there was a sting in the tail as he received a £3,000 fine and seven-day ban for his use of the whip on Leading Light. He was then handed another two-day suspension for a similar infringement on the unplaced Carlo Bugatti later on, meaning he'll miss the Eclipse Stakes at Sandown on July 5.
Frankie Dettori gave his first flying dismount for some time to celebrate his 49th Royal Ascot success with a vintage display on Baitha Alga (8-1) in the Norfolk Stakes.
"He's a dream to ride," said Dettori, who won the Coventry Stakes on The Wow Signal on Tuesday.