But the 3-year-old bay colt, bidding to become the 12th horse to win the Triple Crown and the first in 37 years to win it, burst to the front and took control of the small, eight-horse field and his destiny.
The Belmont Stakes was over before anyone watching the race knew. That is except for trainer Bob Baffert. He and jockey Victor Espinoza understood how great their horse is and, even before the Belmont was halfway done, they were certain they were going to win.
The horse with the misspelled name
led wire-to-wire Saturday, defeating second-place Frosted by a comfortable margin -- 5 1/2 lengths. Keen Ice was third.
"Down the backside he was in his groove and I knew he's a great horse and he was going to do it," Baffert said. "He's just a great horse. It takes a great horse to do (win the Triple Crown)."
The trainer later said: "I could tell by the eighth pole it was going to happen and all I did was just take in the crowd. It was thundering."
American Pharoah is the first Triple Crown winner since Affirmed won the Kentucky Derby, Preakness Stakes and Belmont Stakes in 1978.
Owner Ahmed Zayat, when handed the Triple Crown trophy, said: "I am so thrilled, honored, privileged, humbled, excited."
American Pharoah was the only horse in the race who had run both the Kentucky Derby and the Preakness. But he showed early he didn't have tired legs.
The odds-on favorite started from the fifth post and was slow out of the gate, but given daylight to his inside, he was in the lead before the first pole.
He set a moderate pace, with five of the other seven horses just behind.
Espinoza sensed history early in the race.
"In the first turn it was the best feeling I've ever had," he told reporters.
To the 90,000 fans at Belmont Park, the 1 1/2-mile race was still among a tight group of a half dozen horses. They stayed bunched down the backstretch with American Pharoah slightly ahead.
As he came out of the far turn, he motored to a two-length lead. Finally, the crowd could sense the drought was about to end and roared their approval. American Pharoah wears ear plugs, but the people in the stands were so loud he just might have heard them.
American Pharoah kept extending the lead until crossing the finish line in 2:26.65, the sixth-fastest time in Belmont history.
Baffert said his horse had trained very well and the team had him prepared to win.
Baffert and Espinoza each won their first Triple Crown after multiple prior attempts with other horses.
"I just feel like I have a very special horse and he's the one that won," Baffert, 62, said. "It wasn't me."
Baffert had been frustrated three times before but none was more upsetting that 1998 when his horse Real Quiet dueled with Victory Gallop. Real Quiet won the Derby and the Preakness, and he led the Belmont at the start of the long homestretch. Victory Gallop made up significant ground and won at the wire by a nose.
"I was really getting to dislike this trophy. It's caused me a lot of misery," Baffert said. "I still can't believe it happened. ... I couldn't be any happier."
Third time a charm
Espinoza, 43, also had a record-setting day as the oldest jockey to win the Triple Crown. He is also the first Latino jockey to win it.
"I came here with a lot of confidence, more confidence than the last two (Triple Crown attempts)," he said. "That trophy it caused me a lot of stress ... but the third time was the charm."
Espinoza first competed for the Triple Crown in 2002, but War Emblem faltered and finished eighth at Belmont. California Chrome finished fourth in 2014.
Until Saturday, 13 horses since 1979 had won at Churchill Downs and Pimlico but failed to triumph at Belmont.
In 1978, Affirmed, ridden by Steve Cauthen, defeated second-place Alydar in three exciting races.
Triple Crown winners
1919 -- Sir Barton
1930 -- Gallant Fox
1935 -- Omaha
1937 -- War Admiral
1941 -- Whirlaway
1943 -- Count Fleet
1946 -- Assault
1948 -- Citation
1973 -- Secretariat
1977 -- Seattle Slew
1978 -- Affirmed
2015 -- American Pharoah