Daylami's sire, Doyoun, won the 2,000 Guineas and finished third in the Derby, before a stud career in which he produced the winners of over two hundred races.
Starting favourite as part of a two-horse Aga Khan entry, Daylami was sent into the lead in the straight, but was caught in the closing stages and beaten three quarters of a length by Shaka.
[10] Three weeks later, he beat the same horse, by the same margin, over the same course and distance to win the Group One Poule d'Essai des Poulains on soft ground,[11] with Godolphin's Bahamian Bounty, winner of the Prix Morny and Middle Park Stakes, finishing last of the six runners.
Daylami's striking appearance impressed observers[13] and he was well fancied at 7/2, but in the race he seemed to be outpaced in the closing stages and finished a well-beaten third to Starborough.
On his final start of the year, he finished third in a strong renewal of the Prix du Moulin de Longchamp behind Spinning World and Helissio.
He reversed the form with Faithful Son at level weights to record his most valuable win so far in the Eclipse Stakes at Sandown two and a half weeks later.
[18] Most of the attention was drawn by the fact that Saeed bin Suroor was responsible for training Daylami, Faithful Son and Central Park, giving the Godolphin team first, second and third places in a Group One race.
[19] For his next start, he was moved up to the mile and a half distance for the first time in the King George VI and Queen Elizabeth Stakes in which he was ridden by Mick Kinane, Dettori having opted to ride Swain.
[20] On his final European start of the year, Daylami was brought back to a mile and a quarter and was slightly disappointing, finishing third to the filly Alborada as the 6/5 favourite for the Champion Stakes.
He was then made favourite for the Tattersalls Gold Cup, which had been promoted to Group One level, but after taking the lead in the straight, he was overtaken in the closing stages and beaten two and a half lengths by the Japanese-bred filly Shiva.
This was Daylami's first win over a mile and a half, but the lack of early pace[29] and slow time of 2:40.26 meant that the race did not conclusively prove his stamina.
[32] In July, he was an easy and "impressive" winner of the King George VI and Queen Elizabeth Stakes, taking the lead over a furlong out and pulling away to win by five lengths.
[33] Although Daylami's connections were pleased, with Dettori talking enthusiastically about the "ultimate champion", some observers, including the Independent's correspondent, were less convinced, pointing out that the field for the King George had been well below its usual standard.
Despite his win at Ascot, Daylami started only second favourite behind Royal Anthem, who had recently won the Group One International Stakes at York by eight lengths.
[35] After tracking the leaders in the early stages, Daylami moved through "easily" on the inside to take the lead in the straight and drew right away to win by nine lengths from the filly Dazzling Park, with Dream Well third and Royal Anthem fifth.
The venue, with its warm climate and tight, seven-furlong turf circuit was believed to be particularly challenging for European horses,[40] with none of them having won when the Breeders' Cup was run there in 1989 and 1992.
He produced a powerful late run to take the lead inside the final furlong and stayed on strongly to win by two and a half lengths from Royal Anthem with Buck's Boy third.