Which race was Man o’ War’s only career defeat?

Man o’ War’s only career defeat came in the 1919 Sanford Stakes.

The race was held at Saratoga Race Course when Man o’ War was a two-year-old. He lost by a head to Upset, a result that became one of the most famous upsets in American racing and helped popularize the word “upset” in sporting use.

Man o’ War won 20 of his 21 starts. He did not compete in the Kentucky Derby because his owner, Samuel D. Riddle, did not favor sending horses to the race. Instead, Man o’ War became a major winner in other American events, including the Belmont Stakes and Travers Stakes.

The Sanford Stakes was later renamed the Sanford Stakes in his honor, and Saratoga commemorated the historic result with a race called the Sanford Stakes. Man o’ War retired in 1920 and became an influential sire.