Coventry Stakes by six lengths, and the decision was made to go to France for the Prix Robert Papin at Maisons-Laffitte. After an arduous journey, Mill Reef tasted defeat for the first time by the narrowest of margins to another exceptional English two-year-old, My Swallow. Back on home soil, he was entered in the Gimcrack Stakes at York in mid August. After a torrential overnight downpour turned the going into a quagmire, his trainer wanted to scratch him from the race. However, after discussions with his owner prior to the race, Paul Mellon said, "Let him run, I've a feeling it will be alright." Mill Reef won by ten lengths from Green God (who was crowned champion sprinter the following year). In his next race, he beat the filly Hecla by a length in the Imperial Stakes at Kempton . In his final race of the season, he won the prestigious Dewhurst Stakes at Newmarket by four lengths. In a crop of outstanding two-year-olds, Mill Reef was rated 1 lb below his French conqueror My Swallow, who remained unbeaten in 7 races including all of France's top two-year-old races, and 1 lb ahead of the unbeaten Middle Park Stakes winner, Brigadier Gerard. 1971: three-year-old season As a three-year-old, following a victory in the Greenham Stakes at Newbury, Mill Reef was beaten three lengths in the 2,000 Guineas by Brigadier Gerard, who was to prove himself one of the best milers ever, with his old rival My Swallow back in third. Although his breeding hinted otherwise, Mill Reef then proved himself to be the outstanding middle distance racehorse of the year, winning the Derby by two lengths from Linden Tree, the Eclipse Stakes at Sandown (beating the crack French colt Caro by four lengths) and the King George VI and Queen Elizabeth Stakes at Ascot by six lengths from Derby Italiano winner Ortis. In October, he was victorious in the Prix de l'Arc de Triomphe at Longchamp in France, beating the star French filly Pistol Packer by three lengths. 1972: four-year-old season Kept in training as a four-year-old, Mill Reef returned to Longchamp to win the Prix Ganay in April 1972 by ten lengths. A summer rematch with Brigadier Gerard, who had also been kept in training as a four-year-old, was earmarked for the Eclipse Stakes at Sandown. But after a narrow win in the Coronation Cup at Epsom Downs, by