UAEダービー
On May 2, American Pharoah started as the 2.9–1 favorite in an eighteen-runner field for the 141st running of the Kentucky Derby at Churchill Downs. His opponents included Dortmund, winner of the Santa Anita Derby; Carpe Diem, who won the Breeders' Futurity Stakes and Blue Grass Stakes; Firing Line, winner of the Sunland Derby; Wood Memorial winner Frosted; Florida Derby winner Materiality; international entry Mubtaahij, who earned his way to Kentucky with a win in the UAE Derby; and Upstart, winner of the Holy Bull Stakes. The crowd surrounding the horse during the walk-over from the barns to the paddock upset American Pharoah, and several grooms were required to keep him under control. He continued to misbehave until he was loaded into the starting gate; his connections and supporters worried that he was using up energy he needed for the race.