BALTIMORE — Soaked with sweat, Shackleford bucked and kicked until crewmen finally shoved him into the No. 5 gate at the Preakness.
Less than two minutes after the gate sprang open, the nervous colt was a cool winner.
Shackleford held off a late charge by 2-1 favorite Animal Kingdom, spoiling yet another Triple Crown try and beating the Kentucky Derby winner by a half-length Saturday at Pimlico.
The colt, who led into the stretch in the Derby two weeks ago, finished the wire-to-wire win at 12-1 odds, covering 13/16 miles in 1 minute, 56.47 seconds.
The last horse to sweep the Derby, Preakness and Belmont Stakes was Affirmed in 1978. Big Brown was the last to attempt a Triple, in 2008.
With jockey Jesus Castanon aboard, Shackleford battled Flashpoint for the lead until midway on the final turn and then dug in to hold off onrushing Animal Kingdom before a crowd of 107,398.
"He was a little hot in the beginning, but he was able to calm down," Castanon said. "He's a good horse and able to handle it."
It was the first victory in a Triple Crown race for Castanon and trainer Dale Romans, a Louisville, Ky., native, who watched Shackleford finish fourth in the Derby.
Castanon is a two-time riding champion at Tampa Bay Downs in Oldsmar. He won back-to-back titles beginning in 2003-04. The win also was the first Grade I stakes victory for Castanon, who won his 2,043th career race with nearly $40 million in earnings.
Shackleford often gets nervous and sweats a lot before a race.
"He wasn't acting that bad," said Romans, who also has one Breeders' Cup victory and a win in the $6 million Dubai World Cup to his credit in his long career. "It's a hot day, so that wasn't worrying me too much. I was more concerned at the quarter-pole if he was going to hold on.
"I've won some big races but none as exciting as that one."
Last year in the Preakness, he finished second with First Dude.
Dialed In was fourth after finishing eighth in the Derby as the beaten favorite. "They went fast enough early, but then they slowed out," trainer Nick Zito said. "It didn't work out."
Animal Kingdom trainer Graham Motion, full of hope and expectation at the race's start, looked on glumly as his horse couldn't catch Shackleford.
"He ran huge. I was hoping he was going to get there," said Motion, who had kept the Derby winner at his stable 60 miles away until race morning.
Shackleford broke alertly, as did Flashpoint. They dueled through an opening quarter-mile of 22.69 seconds, a fifth of a second off the Preakness record. "It was fast, but he kind of pulled everyone else out of the race," Romans said.
Castanon got Shackleford to relax into a comfortable rhythm as the pace slowed going down the backstretch. That proved to be a key moment.
"That kind of hurt us," Motion said. "That middle quarter really affected the outcome of the race."
Midway through the final turn, Flashpoint gave up, leaving Shackleford as the lone target for the closers. At the top of the stretch, Animal Kingdom emerged as the main threat. He passed horses in pursuit of the leader while Astrology made a strong run along the rail.
"I felt somebody coming at the sixteenth-pole," Castanon said. "I knew that Animal Kingdom was the only horse who was able to come get me."
Times correspondent Don Jensen contributed to this report.