Hightail won the $500,000 six-furlong Juvenile Sprint on Friday, first race of the two-day, 15-race Breeders' Cup championships at Santa Anita worth a total of $25 million.
Trained by D. Wayne Lukas and ridden by Rajiv Maragh, Hightail went off at 15-1 and came through on the inside in the final stretch to seize the victory by a nose ahead of Merit Man, who broke well and led as they turned for home.
The result stood up after a stewards' inquiry into potential interference between the front two.
Sweet Shirley Mae was third in a field reduced to five runners.
Super Ninety Nine, one of the pre-race favorites trained by Bob Baffert, was scratched Friday morning after suffering minor abrasions when becoming cast in his stall. South Floyd, trained by Doug O'Neill, was scratched at the gate because of slight lameness affecting a front leg.