LOUISVILLE, Ky. — They were not worried, and they said so all week. Everyone had stopped by the barn of the trainer Doug O’Neill and told him that his colt Nyquist did not have the stamina to last a mile and a quarter — that he had cranked up his baby too much in capturing a $1 million bonus last month in the Florida Derby.  There could not be anything left in the tank after that, right? There was no way that a favorite was going to win the Kentucky Derby for the fourth consecutive year, was there?  O’Neill — along with his brother and consigliere, Dennis, and Nyquist’s rider, Mario Gutierrez, and especially the colt’s owner, J. Paul Reddam — just smiled and went about his business. The barn was humming along — think the Google campus, but substitute matted bed head for skinny jeans and piles of dung for beanbag chairs.  What, me worry? That was the response from an outfit that had been here and done it before, four years ago with a long shot named I’ll Have Another. That late-running colt sneaked into Churchill Downs and hid in the shadow of the track’s iconic twin spires without anyone much noticing.  For the 142nd running of the Kentucky Derby on Saturday, there was no hiding. Nyquist was the 2-year-old champion, after all, and the colt was undefeated in seven starts and had beaten at one time or another nearly a quarter of the field assembled here.  Nyquist had a better résumé than last year’s Triple Crown champion, American Pharoah, and had enough black type, as stakes wins and places are called, to rival that of the 1977 Triple Crown champion, Seattle Slew. He was the Big Horse by anyone’s definition.  Nyquist showed why as soon as he slipped out of the gate, a thief in the night, prowling with purpose around the first turn as if he were tethered to the front-runner, Danzing Candy, and were atop the two fattest skis while riding in the wake of a big old boat.  There are not many Kentucky Derbys that can be proclaimed over moments after they have started, but losing betting tickets were being crumpled in knotted fists as soon as Nyquist floated out of the first turn and then skipped down the backstretch as if he had just gotten out of school.  It did not matter that he was chasing a swift front-runner throwing down fast fractions. Gutierrez had Nyquist breezing along unbothered. Horse and rider totally ignored Florent Geroux, who had a colt named Gun Runner ahead and inside them and looked every bit like a horse sniffing the wire first.  Instead, Gutierrez let Nyquist have his head as they came around the far turn and asked for another gear into the stretch. A familiar rival by the name of Exaggerator launched a late run from far back, but his rider, Kent Desormeaux, knew that it was a futile chase.  “My horse slammed on the brakes and ducked back to the inside and then took off,” Desormeaux said after Exaggerator finished second, a length and a quarter behind Nyquist.  Gutierrez did not see Exaggerator or anyone else that he was worried about when he peeked beneath his arm. The rider knows his colt.  “He will not allow any other horse past him,” he said. “He’s the kind of horse that always has something left for whatever comes to him late.”  Bettors were hardly surprised by the outcome: Nyquist was a solid favorite paying $6.60 for a $2 bet. It was a lucrative day for Reddam as well. His colt’s win was worth $1.24 million and lifted Nyquist’s career earnings to more than $3 million.  Now that the Kentucky Derby was over, a bigger race was on. Can it be? Is it possible that a year after American Pharoah took down thoroughbred racing’s holy grail and became just the 12th Triple Crown winner in history — the first in 37 years — that racing could have another?  Again, Reddam and O’Neill took the hypothetical head-on and acted as if it were not only a possibility but their plan.  “He’s such a special horse,” O’Neill said. “We see it in his eyes on a daily basis. He’s the type of athlete that puts his time in the gym every day and goes to bed early. When we go to the track each day, he just swishes his tail and asks, ‘What do you want from me now?’ ”  O’Neill also knows that he will need a whole lot of luck and a little bit of magic to navigate those historic shoals.  The affable O’Neill took a beating throughout I’ll Have Another’s run toward a Triple Crown when it came to light that over 14 years and in four states he had received more than a dozen violations for giving his horses improper drugs and that his horses had a tendency to break down or show signs of injury at a rate more than twice the national average.  When asked if history could repeat itself, O’Neill asked his mother, who was here with him, to light a candle at church on his and his horse’s behalf.  “We need some higher power to keep this guy injury free,” he said.  While Reddam enjoyed his second Derby victory, he could not resist barking back at doubters.  “I feel really good for the horse,” Reddam said, “because along the way the last year, he has taken a lot of shots for whatever reason. And I think he proved all his critics wrong today.”  Reddam could not help offering a pun and keeping hope for another piece of history. In 2012, I’ll Have Another won two-thirds of the Triple Crown before withdrawing from the Belmont Stakes on the eve of the race with a tendon injury.  “We’ll have another,” he said when accepting the Derby trophy.  We will see if another Triple Crown is in the cards.  A version of this article appears in print on May 8, 2016, on page SP1 of the New York edition with the headline: A Thunderous Opening Statement. Order Reprints| Today's Paper|Subscribe
Nyquist, the 2-to-1 favorite, held off the hard-charging Exaggerator at the wire to claim the Kentucky Derby, the first jewel in the Triple Crown.