Frankie Dettori recorded a fairytale victory on his final Gold Cup ride, with the aptly-named Courage Mon Ami showing plenty of grit to down Coltrane in a titanic battle through the final furlong of the Royal Ascot showpiece.

It was a ninth Gold Cup for the Italian, who will hang up his boots at the end of the year.

Courage Mon Ami was having only his fourth lifetime start, having won his three previous races for John and Thady Gosden.

Stepping up in trip, the 15-2 chance was settled near the back of the pack as Subjectivist, the winner two years ago, made most of the running.

But Dettori took a risk and waited on the rail before sweeping through beaten horses and switching outside Coltrane's withers.

The four-year-old son of Frankel kept finding to beat the 11-4 favourite, who was ridden by Oisin Murphy. Subjectivist stuck on well to finish a gallant third.

"Unbelievable! I thought it was a bridge too far from handicaps, but I had the perfect race," said a jubilant Dettori, who returned to a tremendous reception and even gave the Queen a kiss at the presentation ceremony.

"He's still a baby, but when Coltrane came back he picked up again. I can't hear myself talking!"

He went on: "I didn't expect it. The last five years I had Stradivarius so the pressure was on, this one I thought was a bit of a chancer, coming from handicaps, but John was confident.

"I didn't believe it, but I said to him he's pulled a rabbit out of the hat. He's a great trainer and he does things like that. Sometimes if I don't believe it I just go along with it!

"I rode him cold and it just happened. I got the splits when I wanted to and in fairness he showed a turn of foot.

"In the last half a furlong I couldn't get rid of Oisin and I thought 'no, we've got this far, please keep going!'.

"Nine Gold Cups, what can you say? I'm speechless, to be honest."

King Charles III claimed his first Royal Ascot winner as the reigning monarch.

Watching the race alongside Queen Camilla from the Royal Enclosure, the King saw Desert Hero - wearing the royal silks and an 18-1 shot - win by a short head in the King George V Stakes on Thursday.

"Royal winners at the royal meeting are extremely special, especially this one," jockey Tom Marquand said. "It will live high in my career, probably at the top for the rest of my days in the saddle."

The late Queen Elizabeth II was a big fan of horse racing and had 24 winners at Royal Ascot in her long reign.

with AP