[2] He was bred at Crichel in Dorset by Henry Sturt, 1st Baron Alington,[3] who owned him during his racing career in partnership with Sir Frederick Johnstone.

[4] The colt was first sent into training with Lord Alington's private trainer H. Percy in Dorset, but was moved at the end of his two-year-old season to the stables of John Porter at Kingsclere.

St. Blaise was then sent to Goodwood for the Molecomb Stakes in which he dead-heated for first place when attempting to give seven pounds Elzevir,[2] a horse who went on to win the Royal Hunt Cup.

[10] St. Blaise grew and made good physical progress[10] during the winter and in mid-April he appeared for the first time in the Derby betting lists at 33/1.

[14] Shortly before the Derby, St. Blaise and his connections travelled to Epsom and stayed nearby at an inn called the Sheepshearer's Arms at Burgh Heath.

The race took place in fine weather in front of an "immense" crowd which included the Prince and Princess of Wales and other members of the royal family.

[17] St. Blaise, ridden by Charles Wood, was held up in the early stages as the pacemaker Bonjour made the running but moved into contention at Tattenham Corner.

In the final furlong St Blaise ran on gamely to win a "most exciting race"[19] by a neck (other reports say a head[20]) from Highland Chief with Galliard half a length further back in third.

The Prince of Wales, who had won a reported £5,000 on the race, was among the first to congratulate his owners[21] and later hosted a "brilliant party" to celebrate St Blaise's victory.

One version of the conspiracy theory claimed that Highland Chief crossed the line in front,[23] but that the racecourse judge awarded the race to St. Blaise because he wanted to frustrate the plans of the Archer brothers.

St Blaise and the French colt had a "splendid race" in the closing stages, but although the Derby winner steadily reduced the margin between them he could not overhaul the leader and was beaten by a head.