Orb made a last-minute come from behind surge to win the 139th Kentucky Derby, the first jewel in horse racing's famed Triple Crown.
Orb was a 6-to-1 favorite along with Revolutionary, going into Saturday's race at Churchill Downs in Louisville, Kentucky.
Orb trailed the 19-horse field badly nearly the entire race before jockey Joel Rosario brought him up the middle in the final stretch and across the finish line.
Long shot Golden Soul finished second and Revolutionary was third.
It was also the first Kentucky Derby win for veteran trainer Shug McGaughey, who has won nearly every major race in his storied career except the derby.
Next up for Orb will likely be the Preakness in Baltimore, Maryland in two weeks followed by the Belmont Stakes in New York on June 8, the other two races in the Triple Crown series.
No horse has won the Triple Crown since Affirmed in 1978.