Authorized (horse) appeared at the time to be the best performance in any of the 2007 Trial races for the Epsom Derby and Authorized was made favourite for the race. Media attention ahead of the Derby focused on Frankie Dettori who, despite winning all the other British Classics at least twice each, had so far failed to win the Derby in 14 attempts. For the race itself, run at Epsom Downs Racecourse on 2 June 2007, Authorized was a clear favourite at odds of 5 to 4, and justified the odds by winning by five lengths in a fast time. Dropped back
Joe Mercer (jockey) soft going Mercer kept this John Dunlop trained colt towards the rear but steered him up the centre of the course to win a final big victory. The horse and jockey were cheered loudly all the way from the course to the unsaddling enclosure. Mercer's career total of 2,810 winners was exceeded only by Sir Gordon Richards, Lester Piggott, and Doug Smith at the time of his retirement, and subsequently only bettered by Pat Eddery (his niece's ex-husband), Willie Carson and Frankie Dettori. Shortly after his retirement, he was the subject of a biography by Richard Baerlein: "Joe Mercer The