One of these was Fleur by Victoria Park, who produced the 1977 Epsom Derby winner The Minstrel by Northern Dancer; the other was Minsky, champion Irish two-year-old in 1970 and full brother to Nijinsky.

[4] Nijinsky was a big, powerful and handsome horse with great presence, standing 16.3 hands (67 inches, 170 cm) high, resembling his dam rather than his sire in stature and conformation, traits he tended to pass on to his offspring.

[5] He was offered for sale at the Windfields Farm's annual yearling auction where he was bought for $84,000 (equivalent to $740,000 in 2023) by the American minerals magnate and industrialist Charles W. Engelhard Jr., acting on the advice of the Irish trainer Vincent O'Brien.

Ridden for the first time by Lester Piggott, he was held up at the back of the six-horse field before moving through easily to take the lead inside the final furlong, earning top rating in the British Free Handicap.

[7][8] On his first appearance as a three-year-old, Nijinsky beat the four-year-old Deep Run[9] in the Gladness Stakes at the Curragh in April.

Nijinsky took the lead two furlongs from the finish and, without being put under any pressure by Piggott,[10] pulled clear to win by two and a half lengths from Yellow God.

[11] The veteran French trainer Etienne Pollet had delayed his retirement for a year to guide Gyr, a son of his champion Sea-Bird, through his three-year-old season.

[7] Nijinsky was held up by Piggott as usual before moving forward in the straight, by which time Gyr was in front and pulling clear of the Prix Lupin winner, Stintino.

The favourite responded immediately, catching Gyr in a few strides and pulling ahead to win from him by two and a half lengths, with Stintino third.

[17] In July, Nijinsky raced against older horses in the King George VI and Queen Elizabeth Stakes at Ascot.

His five opponents included winners of major races: Blakeney (1969 Epsom Derby), Karabas (Washington, D.C. International Stakes), Crepellana (Prix de Diane) and Caliban (Coronation Cup).

Without being extended, Nijinsky moved through to take the lead a furlong from the finish and won by two lengths from Blakeney despite being eased down to a canter in the closing stages.

[16] Nijinsky appeared to be recovering after being placed on a "rich" diet including raw eggs and Irish Stout,[19] and was sent to Doncaster for the St. Leger in September.

In the one mile and six furlongs race, he was attempting to become the first horse since Bahram 35 years earlier to complete the English Triple Crown.

In the last strides, Nijinsky appeared to veer left away from Piggott's whip,[21] and Sassafras, ridden by Yves Saint-Martin, produced a renewed effort to regain the advantage and win by a head.

[29] In 2018 Nijinsky was rated the greatest-ever Epsom Derby winner by a panel of experts assembled by the Daily Telegraph.

[34] Piggott added later that Nijinsky, during the summer of 1970 when he won the 2,000 Guineas, Epsom Derby, Irish Derby and King George VI and Queen Elizabeth II Stakes, was "an unbeatable horse"[35] Piggott was adamant, however, that running in the St Leger led to the horse not winning at Longchamps.