Inspiral was a breathtaking winner of the Coronation Stakes to give jockey Frankie Dettori something to celebrate at this year's Royal Ascot meeting.
The unbeaten 15-8 favourite, trained by John and Thady Gosden, surged clear on her seasonal return from runner-up Spendarella, with Discoveries third.
A day earlier Dettori had been beaten on record-seeking Stradivarius and two horses owned by the Queen.
"It's been a tough week. We're on the board and can chillax a bit," he said.
Dettori treated racegoers to his trademark flying dismount after a four-and-three-quarter-lengths victory on the daughter of Frankel, owned by Cheveley Park Stud.
Ascot's dress code was relaxed as temperatures reached 30C, with massive misting fans in the paddock plus lots of water buckets to help cool horses down.
Inspiral was slowly away from the stalls for Dettori, who received some criticism for his ride on third-placed Stradivarius for the Gosdens in the Gold Cup, and was twice runner-up for the Queen on stablemates Saga and Reach For the Moon.
But the Italian jockey kept his cool on the filly, who had been ruled out of last month's 1,000 Guineas, and she found another gear to storm clear of her rivals for a fifth career triumph.
"She's very special. She's got an engine and she got me out of trouble," said the rider.
John Gosden said Dettori had "got the monkey off his back" with the victory but the trainer said Saga should have won and again questioned his ride on Stradivarius.
"Our hero overcomplicated it yesterday. It's over, it's the past and we move on," said Gosden.
Earlier, Perfect Power secured a second successive Royal Ascot win by taking the Commonwealth Cup.
Trainer Richard Fahey was in tears as he called his winner, the 7-2 joint favourite ridden by Christophe Soumillon, "fantastic".
It was a third top-level Group One victory for Perfect Power, who also won the Norfolk Stakes last year.
Flaming Rib (14-1), part-owned by former England footballer Michael Owen, was second, with 40-1 outside Flotus third.
The 11-2 shot Candleford was guided to an impressive win in the Duke of Edinburgh Stakes by jockey Tom Marquand for trainer William Haggas.
Candleford is owned and bred by Barnane Stud, run by former England cricketer Craig Kieswetter and his family.
"I'd much rather have a winner here I think," he said when asked to compare the victory with his playing career. "It's a lot more fun and there's a lot more champagne to drink."
Ryan Moore led from start to finish on the Aidan O'Brien-trained Meditate (5-2) to win in the Albany Stakes.
Moore followed up later with Chester Vase winner Changingoftheguard, the 11-10 favourite, to narrowly take the King Edward VII Stakes from Grand Alliance and give the trainer his 80th Royal Ascot win.
O'Brien is now just two short of Sir Michael Stoute's record 82 victories at the meeting and has a total of 899 top-level Group triumphs around the world.
Hayley Turner joined Holly Doyle as the most successful female rider at Royal Ascot with her third victory coming on 5-1 chance Latin Lover in the Palace of Holyroodhouse Stakes. It was a first runner at the meeting for trainer Harry Eustace.
Heredia justified 7-2 favouritism in the Sandringham Stakes for Richard Hannon and Sean Levey to give the jockey a first Royal Ascot winner.
The Dark Angel filly drifted left late on, impeding eventual runner-up Zanbaq, but was confirmed the winner after a stewards' inquiry.
What's happening on Saturday?
Australian trainer Chris Wall, who won the King's Stand Stakes with Nature Strip on Tuesday, saddles likely favourite Home Affairs in the Platinum Jubilee Stakes.
The Queen's last hope of a winner at Royal Ascot in her Platinum Jubilee year comes with King's Lynn, while Grenadier Guards bids to become the first Japanese-trained winner at the meeting.
Fresh and Blackrod are among contenders in the Wokingham Stakes on the final day.
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