Magical, one of horse racing's recent stars, has been retired with immediate effect after being ruled out of this weekend's Breeders' Cup meeting.
The four-year-old filly, trained by Aidan O'Brien, won the Champion Stakes at Ascot earlier this month.
She had been a leading contender for the Breeders' Cup Filly and Mare Turf race at Santa Anita on Saturday.
But the daughter of Galileo has been retired after a temperature meant she could not travel to the United States.
Magical won nine races during her career, including four Group One contests, and finished second to wonder mare Enable on three occasions.
She is now set to begin a breeding career, with the sire No Nay Never lined up to be her first partner.