May 7 (UPI) -- Rich Strike scored one of the biggest upsets in the 148-year-history of the Kentucky Derby on Saturday at Churchill Downs in Louisville, Ky., rallying up the rail to upset 19 better-fancied rivals just hour after got into the race as a replacement runner.

Rich Strike followed a blazing pace set by the two foreign runners, found himself perfectly placed as the field hit the final furlong and made his winning move along the rail.

Epicenter, the favorite, was second, Zandon, the third favorite, was third.

Rich Strike, a Keene Ice colt, was claimed for $30,000 by trainer Eric Reed last September from breeders Calumet Farm. He was not supposed to be in the field, drawing in as an also-eligible Friday morning when Ethereal Road was scratched.

"I don't know," Reed said when asked how his bargain-basement colt won America's biggest race. "I fell down in the paddock when he hit the wire," Reed said.