[3] Ambrosio made his first appearance at York Racecourse on 27 May, when he ran in a weight-for-age sweepstakes run in a series of ten furlong heats, with the prize going to the first horse to win twice.

He made his first appearance for his new owner at York in August, when he won a two-mile sweepstakes from Giles Crompton's colt Cardinal and a similar race three days later.

Ambrosio returned to Newmarket in October when he finished second to the filly Doubtful in a sweepstakes before winning a 200 guinea match race against Mr Howorth's six-year-old Lop.

[11] Ambrosio began his five-year-old season (when he raced exclusively at Newmarket) at the Craven meeting on 11 April when he won the third class of the Oatlands Stakes from Sir Frank Standish's four-year-old Stamford, the beaten favourite in the previous year's Derby and St Leger.

This race marked the second and final racecourse appearance of the Colt by Fidget who finished last of the seven runners[12] At the next Newmarket meeting on 24 April, Ambrosio won the main class of the Oatlands Stakes, beating Stamford and Stickler under top weight of 121 pounds.

He ended his season at the Second October meeting when he successfully conceded ten pounds to John Lade's horse Oatlands in a 200 guinea match race.

[17] In August, Ambrosio raced in the north of England for the first time since his three-year-old season when he contested a division of the Great Subscription Purse at York.

He was beaten by Sir Thomas Gascoigne's Timothy, but ended his career with a win later the same afternoon, when he successfully conceded nine pounds to Lord Fitzwilliam's Wonder.

By 1803 he had moved to Barham Wood, near Elstree in Hertfordshire where he stood at a fee of ten guineas and was being advertised as "the best son of Sir Peter".