Upset was the only horse who ever defeated Man o' War! Man o' War was extremely successful horse who won 20 of his 21 starts in his career. Upset defeated him in the seventh running of the Sanford Memorial Stakes at Saratoga Race Course on August 13, 1919, old only two years (Upset was foaled in 1917). Upset victory came as a big surprise to fans and the track officials. Man o' War was still undefeated at the time, having won the Travers Stakes, the Whitney Handicap, and the American Derby. He was a favorite to win the 1919 Kentucky Derby.