I'll Have Another will try to become the first horse since 1978 to win the American Triple Crown following his victory in the Preakness Stakes at Pimlico.
The Doug O'Neill-trained colt added to his dramatic Kentucky Derby defeat of Bodemeister with a similarly thrilling neck triumph over the same rival.
I'll Have Another will now bid for Triple Crown glory in the Belmont Stakes in New York on 9 June.
"The great part of I'll Have Another is that any of us could have a horse like this," O'Neill said.
O'Neill added: "He didn't cost a million bucks. But he's got the heart of a champion, the stride of a champion, and the mind of a champion.
"On to New York, baby!"
The last horse to have won the Triple Crown was Affirmed.
Bodemeister's trainer, Bob Baffert, said: "I felt really good about where he was. He looked like he was travelling nicely. Turning for home I really felt he would win. But the winner is a really good horse. I really can't complain. The California horses are really tough."