Prove Out (1969–1990) was an American thoroughbred racehorse best known for his wins over Secretariat in the 1973 Woodward Stakes, and Riva Ridge in the 1973 Jockey Club Gold Cup.
[2] In the 1973 Woodward, Prove Out, at odds of 16:1, upset odds-on favorite Triple Crown champion Secretariat by 41⁄2 lengths, while conceding 7 pounds to the eventual 1973 Horse of the Year.
[3] Prove Out also defeated Secretariat's stablemate, the 1972 Kentucky Derby winner and 1973 U.S. Champion Older Horse Riva Ridge, in the 1973 Jockey Club Gold Cup.
[1] Prove Out's winning performance in the 2 mile Jockey Club Gold Cup was timed in 3:20, bettered in American racing only by the great Kelso.
In a span of two months Prove Out decisively defeated four Hall of Fame horses: Forego, Secretariat, Cougar II, and Riva Ridge.