It was a case of musical saddles.

When pre-race favorite Uncle Mo was scratched from the Kentucky Derby on Friday, his rider, John Velazquez, picked up the mount on Animal Kingdom, whose designated rider, Robby Albarado, had been injured prior to a race on Wednesday.

The difference between Uncle Mo and Animal Kingdom amounted to more than $1 million in past performances. But Saturday, May 7, was a new day, albeit without Breeders Cup Juvenile champion Uncle Mo.

Animal Kingdom, dismissed at 30 to 1 on the morning line, and at 20 to 1 by the public at post time, picked up momentum and kicked into over drive to sail past Nehro and second-favorite Mucho Macho Man to win the Kentucky Derby by 2 lengths, in 2:02.04. Post time favorite Dialed In was never a factor in the 19-horse field. Nehro finished second, with Mucho Macho Man at third.

Trained by Graham Motion for Team Valor, founded by Barry Irwin, a former staff writer for BloodHorse, Animal Kingdom came into the Derby with 2 wins and 2 seconds out of 4 starts. But his last start had come six weeks before the Derby, on an artificial surface and in the G3 Spiral Stakes, not considered to be a major Derby prep race.

Animal Kingdom won the Spiral, his second start at three, but he had never raced on a dirt surface prior to the Derby.

“You’re always hoping … but I just couldn’t see it happening,” Irwin said of Animal Kingdom’s win. “When it did, I was overwhelmed.”

It was the first Kentucky Derby win for Hall of Fame rider Velazquez, as well as for Team Valor and trainer Graham Motion. Motion had high hopes for Toby’s Corner in the Derby, but had to scratch the G1 Wood Memorial winner on Tuesday because of a training injury.