Nyquist is still undefeated after taking the lead on the final turn to win the Kentucky Derby at Churchill Downs.
Danzing Candy led through the first half of the race before being overtaken by Gun Runner and Nyquist.
Exaggerator made a late charge, but could not catch Nyquist, who was the prohibitive favourite and is now 8-0.
Nyquist is the first Derby winner to start his career eight-for-eight since Majestic Prince in 1969.
"It's unreal," said jockey Mario Gutierrez, who has won both of his Derby rides.
"It's amazing. To see everything turn into reality, there are no words for it."
Nyquist will try to replicate what American Pharoah did last year by going on to win the Triple Crown.
American Pharoah was the first horse to win the Triple Crown since Affirmed in 1978, which was also the last time there were consecutive Triple Crown winners.