Castledale, who won the Generous Stakes (gr. IIIT) on turf late last year, earned $450,000 for his first grade I victory for owners Frank Lyons and Greg Knee.
Runner-up Imperialism will "probably go" on to the Run for the Roses, according to trainer Kristin Mulhall. The gray son of Langfuhr originally finished third, but was bumped up to second after checking hard along the rail when actual runner-up Rock Hard Ten crossed in front of him shortly before the wire.
"He's laying down a lot today," the 21-year-old trainer said. "But he did the same thing after his last race so I know he's OK. I went in there and lay down with him for a while.
"He ate so much dirt (in the race) my vet said she'd never seen so much dirt in a horse's lungs after a race. I honestly think that if he had been outside he would've won. A lot of people thought he was stopping, but Victor (jockey Espinoza) said he was full of run."
Jason Orman, who sent out lightly raced Rock Hard Ten to a second-place finish in his first-ever grade I, was as encouraged by the nearly black colt's performance on Saturday.
"That's horseracing," Orman said. "But he ran good and I'm proud of him. He's doing good today and we'll make a decision on what will happen next in a few days I'd say."
Orman said the decision will depend heavily on the colt's chance of qualifying for the Run for the Roses.
"We probably won't have enough money (earnings to qualify)," Orman said of the $90,000 third-place check the colt earned in his first graded stakes. "The disqualification might really affect us there, so we'll see."
Orman indicated that Rock Hard Ten may head to Louisville to prepare for the Derby and play the waiting game.
Fourth-place finisher Quinton's Gold Rush will start next in the April 17 Coolmore Lexington Stakes (gr. II) at Keeneland, trainer Mike Mitchell said. The chestnut colt will be transferred to the care of Midwest-based trainer Steve Asmussen.
Fifth-place finisher Wimbledon goes on to the Derby, trainer Bob Baffert confirmed.
"He was too close to the pace and got a little tired," Baffert said. "But he's all right. We'll go on. I know he's a good horse. He's already shown that. I really think he's a better horse when he leaves Santa Anita anyway. This is not his kind of surface. I think we learned more from this loss than we did from winning in Louisiana. You learn from your losses and you kick yourself in the butt."
Trainer Rafael Becerra had no excuses for favored St. Averil's sixth-place finish.
"He's doing much better today than I am," Becerra said. "He's well, I'm disappointed. I don't know what happened but (jockey Tyler Baze) had to ride him hard all the way. I knew it was over at the half-mile pole when everyone was making a move and he wasn't.
"The (Kentucky) Derby is still an option. I have to talk to (owner) Mr. Fulton and we'll make a decision in 10 days or two weeks. He has enough earnings get in, so we'll see."