A sterling performance by Cheyenne Stables’ Mastery in the $400,000 San Felipe Stakes (G2) for a moment appeared to stamp him as the clear favorite for the Kentucky Derby Presented by Yum! Brands (G1).

The undefeated son of Candy Ride set the pace, turned away a challenge from grade 1 winner Gormley and San Vicente (G2) winner Iliad, and pulled away in the stretch to win by 6 3/4 lengths. But Mastery was pulled up by Mike Smith after the wire and the Hall of Fame jockey jumped off the colt in the turn.

Cheyenne owner Everett Dobson said after the race that Mastery sustained a condylar fracture in his left front leg and will undergo surgery “in a few days.”

“It will require a few screws to be inserted and he’s going to have to take some significant time off—several months off,” Dobson said. “Obviously it’s incredibly disappointing. It’s difficult to find horses of this talent and have them run in your colors.”

Smith said he felt something wrong about “10 jumps” after the wire.

“Something went off on the left hind. I don’t know why,” Smith said immediately after the race. “It wasn’t something that happened that made me think, ‘Oh (something wrong) happened.’ He just all the sudden went off it and wouldn’t put any weight on the left hind.

“I got off real quick and nothing is dislocated and everything seemed fine, and after he moved for a little bit, he started walking fine on it. I’m hoping maybe he just tweaked it or rolled it and that it’s nothing serious, because he’s an incredible horse.”

Trainer Bob Baffert was making his way down to the winner’s circle after the victory when a fan alerted him something had gone wrong.

“We’ve been so high on this horse and you see what he did today, which was incredible … and I’m walking down and I hear one of the fans say, ‘I hope your horse is all right,'” Baffert said.

The trainer later said that the colt will be re-evaluated after surgery.

“We won’t know until after the surgery whether or not this will be career ending,” Baffert said.

Mastery hit the front soon after the start, with Gormley stalking, and Iliad just off the top two, three wide. Mastery set fractions of :23.50, :46.79, and 1:10.48 through six furlongs, when Gormley mounted his serious challenge. As Gormley began to drop back, Iliad loomed as a challenger, but Mastery effortlessly pulled away in the stretch. His margin over Iliad was two lengths with a furlong to run, and he extended it with each stride to the wire to finish off the 1 1/16 miles in 1:42.28.

“This is a really talented horse,” Smith said. “The power is endless with this guy. He’s some kinda strong. He was hitting gears every time I asked him to. … Everything seemed to come easy to him. That was a pretty impressive race. I’m just hoping everything is OK.”