The extraordinary Justify roared to an imperious victory in the Belmont Stakes in the fading daylight of Saturday afternoon, becoming the 13th horse to win thoroughbred racing’s Triple Crown and only the second in four decades.

The strapping chestnut colt with the white blaze running from his eyes to the tip of his nose, trained by Bob Baffert and rode by Mike Smith, broke well out of the gate and went right to the front, leading from wire to wire and finishing in a time of 2:28.18 amid a deafening roar from the crowd of 90,327 at Belmont Park, the venerable race course just outside New York city limits.

Running from the unenviable No1 post, Justify galloped through fractions of 23.37 seconds for the opening quarter-mile, 48.11 for the half, 1:13.21 for three quarters and 1:38.09 for the mile and was never seriously challenged in the grueling one-and-a-half-mile race, settling into an easy rhythm under a soft pace down the backstretch of the sprawling oval known as Big Sandy and coasting home, the last horse asked to run, as the delirious cheers from grandstand rose and rose again. The clean glimmer of his magnificent copper coat as he breezed through the wire stood in stark relief with the nine soiled foes he’d vanquished: quite literally, he left them in his dust.

“This horse ran a tremendous race,” said Smith, who at 52 is the oldest jockey to complete the rare sweep of America’s three most famous races. “He’s so gifted. He’s sent from heaven. He’s just amazing. I can’t describe the emotions going through my body right now.

“Did you see him standing in the gate? He’s standing so still, I actually thought he’s not going to break today. I mean, he left there like he was going 440 yards in Riodoso, New Mexico.”

Gronkowski, making his US debut after shipping from England, rallied from a disastrous start and picked off a half-dozen rivals in the final two furlongs to finish second, one-and-three-quarters lengths back. Hofburg was third and Vino Rosso fourth, followed by Tenfold, Bravazo, Free Drop Billy, Restoring Hope, Blended Citizen and Noble Indy.

Justify wins the 150th running of the Belmont Stakes to complete a sweep of America’s three most famous races.

“You can’t doubt [Justify] now, there’s no way,” said Bill Mott, who trained Hofburg. “You’ve got to give him credit. He did it right up on the pace and everybody had an opportunity to take their shot. They didn’t do it today. They let it go too easy.”

Justify went off as a prohibitive 4-5 favorite and paid $3.60, $3.50 and $2.80, running the final quarter-mile in 25.28 seconds and becoming the first ever Triple Crown winner to defeat nine opponents at Belmont. (None of the previous dozen had beaten more than seven.)

The three-year-old son of Scat Daddy and Stage Magic, who is collectively owned by China Horse Club, WinStar Farm, Starlight Racing and Head of Plains Partners, didn’t compete in a race until the third week of February, but has now won every start of his compressed career, a total of six in 111 days with five of them going two turns, and becomes the second undefeated horse to win the Triple Crown after the great Seattle Slew – and the only one of the entire lot to have not raced as a two-year-old.

From unknown to unrivaled in 16 weeks.

“To win six races in such a short amount of time like he’s just done is just an unbelievable feat on his part,” Smith said. “Really Bob has just done a tremendous job to get this horse to do what we just got done doing.”

Justify, right, with jockey Mike Smith, crosses the finish line to win the 150th running of the Belmont Stakes. Photograph: Julio Cortez/AP

After making his debut at Santa Anita and winning an optional-claiming race the next month, Justify became the first horse in 136 years to win the Kentucky Derby without having raced as a juvenile, then hung on in a surreal fog to win by a half-length in the Preakness three weeks ago. After laboring to win the first two jewels of the Triple Crown on sloppy courses, he coasted in Saturday’s one-and-a-half-mile clincher on a track rated fast beneath an overcast sky on an 80F afternoon.

Now the prodigious colt has completed what’s been called the most difficult feat in American sports: winning three races at three different distances in three different states over a five-week span. He enters a storied roll of equine athletes to sweep the Derby, Preakness and Belmont, joining Sir Barton (1919), Gallant Fox (1930), Omaha (1935), War Admiral (1937), Whirlaway (1941), Count Fleet (1943), Assault (1946), Citation (1948), Secretariat (1973), Seattle Slew (1977), Affirmed (1978) and American Pharoah (2015).

Baffert, 65, for so long intimately familiar with Triple Crown heartbreak after he was thwarted in bids at the Belmont with Silver Charm (1997), Real Quiet (1998, by a nose) and War Emblem (2002), has now completed the sport’s pinnacle achievement twice in four years.

“It’s just amazing,” the Hall of Fame trainer said. “It never gets old. American Pharoah, he’ll always be my first love, (but) Mike Smith, he deserves something like this.”

He added: “[This horse] was showing me the same signs [as American Pharoah], he showed me that same brilliance. Superior horse. I mean, he could have won every race on the undercard today. He’s just that kind of horse.”

The silver-haired Californian becomes only the second trainer to saddle more than one Triple Crown winner after ‘Sunny’ Jim Fitzsimmons, who trained Gallant Fox and his son Omaha between the wars.

“I think of my parents, I think of all the good friends I’ve lost, and I know they’re up there, that they’re helping me out, giving me that little push,” Baffert said. “I think things happen for a reason. If it was meant to be, it was meant to be. I knew this horse was doing well. We had him ready, but that horse, it was just ... just to train a horse like that, he’s just a magnificent animal.

“I’m just glad that I got a chance to train a horse like that.”