In only his second career start, 25-1 outsider Authorized powered home to win the Racing Post Trophy Stakes (Eng-I) at Newbury on Saturday.
The Peter Chapple-Hyam trainee won by 1¼-lengths over fellow longshot Charlie Farnsbarns (33-1). Medicine Path (20-1) was two lengths further back in third.
Prince Golan led the field during the early stages of the race, with Malacara and Drumfire in close pursuit.
The race was still wide open three furlongs out, with a host of horses still in with a chance. Petara Bay and Charlie Farnsbarns made their bids, but Authorized came fast and late to grab the last Group 1 of the year in England.
Winning jockey Frankie Dettori told Channel 4 Racing: "I must say I have to thank the owner, as I tried to put him off running the horse, as mentally I didn't think the horse was ready for this kind of field. We knew he had the talent and the race went very smoothly. He won like a good horse."
Authorized is a 2-year-old bay colt by Montjeu out of Funsie, by Saumarez. His female family has produced other top 2-year-olds Green Dancer and Okawango.