The woman, who asked to not be identified, correctly picked the top five horses, including winner Justify, in order of their finish.
The payout made her nearly as much as the owners of Justify, who brought in $1.24 million.
“It’s extremely rare,” said Rachel Bagnetto, spokeswoman for Retama Park. “To bet that little amount of money and win $1.2 million is unheard of. In fact, it’s the first time it’s happened at Retama.”
Justify, the 5-2 favorite, became the first Derby winner in 136 years that did not race as a 2-year-old. The chestnut colt has won all four starts as a 3-year-old.