Originally named Abraham Newland, he was renamed to reflect the sporting interests of Henry Tempest Vane who bought the horse in the summer of his three-year-old season.
After bolting on his racecourse debut, Cockfighter was undefeated for more than two years, winning the St Leger, the Doncaster Cup, and three divisions of the Great Subscription Purse at York, and was regarded as the best horse in Northern England.
He started the 7/4 favourite for the four mile Richmond Gold Cup and won from Baron Nile, a grey colt owned by Mr Alderson.
Ridden by his trainer Tom Fields, he started the 4/6 favourite and won from Mr Cookson's colt Expectation, with Sir Thomas Gascoigne's brother to Symmetry in third place.
[7] The Sunday after the St. Leger, Tempest Vane reportedly rode Cockfighter as a hack through Hyde Park, which attracted some notoriety as the horse was deemed valuable.
[10] In 1801, Cockfighter was scheduled to begin his season with a match against Warter at the Newmarket Craven meeting in April, but his opponent failed to appear, allowing Tempest Vane to claim 500 guineas in forfeit.
[12] Cockfighter had won his last nine competitive races and was regarded as the champion of the North,[13] by the time he appeared at the St Leger meeting at Doncaster, where he had two engagements.
On 19 September he lost for the first time in over two years when he was defeated by Mr Johnson's horse Sir Solomon in a match race over four miles at level weights.
[14] Four days later, Cockfighter started the odds-on favourite for the Doncaster Stakes, but finished third of the four runners behind Chance, a four-year-old colt owned by Mr Wentworth.
He finished third to Haphazard and Chance when carrying top weight of 121 pounds in a four mile handicap race, and was beaten by Sir Solomon in the older horses' division of the Great Subscription Purse.