The Fugue, winner of last month's Prince of Wales's Stakes at Royal Ascot in record time, has been retired because of a leg injury.
John Gosden's five-year-old filly suffered a knock in last weekend's Coral-Eclipse Stakes at Sandown.
Owned by composer and theatre producer Andrew Lloyd Webber, The Fugue was a four-time winner at Group One level.
"The Fugue has been a pleasure to train," said Gosden. "She never ceased to amaze us with her athletic ability."
He added: "Unfortunately, The Fugue sustained an injury to her near fore in the Eclipse Stakes. We have taken the decision, in the best interests of the filly, to retire her from racing."
Having scored on her debut as a two-year-old at Newmarket in October 2011, The Fugue finishes her career with a record of six wins and seven places from 17 starts.