On his three-year-old debut, Doyoun appeared at Newmarket in April for the Craven Stakes, a trial race for the 2000 Guineas in which he was matched against Warning, the previous season's top-rated two-year-old.

[1] Swinburn tracked the leaders before sending the colt into the lead two furlongs out, but on this occasion he was unable to break clear of the field and was "all out" to hold off the challenge of Charmer by half a length.

[6] Racing on softer ground in the King George VI and Queen Elizabeth Stakes at Ascot in July, Doyoun weakened in the closing stages and finished sixth of the ten runners behind Mtoto.

On his final appearance, Doyoun ran over ten furlongs in the Champion Stakes at Newmarket in October, and finished third to the filly Indian Skimmer, beaten seven lengths.

In their book A Century of Champions, based on a modified version of the Timeform system, John Randall and Tony Morris rated Doyoun a "poor" winner of the 2000 Guineas.

[8] While admitting that he was not the best of classic winners, Michael Stoute called Doyoun "very honest and a joy to train", whilst Walter Swinburn described him as "a really tough, gutsy racehorse".