An injury to Animal Kingdom's regular rider, Robby Albarado, cleared the way for Velazquez to pick up the mount and once he took the reins on Saturday, he rode his good luck all the way to the winner's circle.
Animal Kingdom, who'd never raced on dirt before, reacted to his new rider the way a champion should, charging down the middle of the stretch to win by 2¾ lengths.
Nehro was second and Mucho Macho Man was another neck back in third.
Dialed In went off as the 5-1 favorite, but finished eighth.
The victory is the first Derby win for trainer Graham Motion and provided redemption for Velazquez, who was set to ride Uncle Mo before the horse was scratched due to a lingering stomach problem.
Albarado broke his nose when he fell off a horse during a post parade at Churchill Downs earlier in the week, then got kicked in the face.
"It's words that you can't describe," Velazquez said. "But I do really feel really bad for Robby. I hope he's winning the Derby with me here. I know he got hurt so this is for both of us, buddy. I know you're not on it, but I know you're with me."
Animal Kingdom went off as a 20-1 longshot in the lightly regarded field. He won the Spiral Stakes on the synthetic surface at Turfway Park on March 26, but had never before run on dirt.
He looked right at home under the twin spires.
Velazquez deftly kept Animal Kingdom out of trouble in the 19-horse field and the colt covered the 1 1/4-mile distance in 2:02.04.
Arkansas Derby winner Archarcharch, who started from the rail, was vanned off the track with a leg injury and was taken to the backside barns for an X-ray.
Former University of Louisville defensive lineman Amobi Okoye and other professional athletes were in Louisville to watch equine athletes show their stuff in the 137th Kentucky Derby.
For Okoye, who plays for the NFL's Houston Texans and was attending his fifth Derby, it was a chance to root long shots Watch Me Go and Master of the Hounds.
"I haven't missed it since college," Okoye said.
Former University of Kentucky point guard John Wall, now of the NBA's Washington Wizards, University of Louisville basketball coach Rick Pitino, who ran fourth-place finisher Halory Hunter in the 1998 Kentucky Derby, and Arizona Cardinals safety Kerry Rhodes, a University of Louisville alumnus, made the scene at the Run for the Roses.
Sarah Ryan of Green Bay, Wis., is a Green Bay Packers fan who hoped to catch a glimpse of Super Bowl MVP quarterback Aaron Rodgers at her second Derby. By midafternoon, Ryan hadn't seen Rodgers, who attended the race in 2009 and 2010, but had seen other celebrities.
"I love everything about it, the whole scene," Ryan said.
Hall of Fame quarterback Warren Moon, Olympic figure skater Sarah Hughes, who won a gold medal at the 2000 games, and New Jersey Nets coach Avery Johnson, a former point guard, also strutted down the red carpet outside Churchill Downs on Saturday.
