[4] On 10 October Enthusiast made his debut in the Middle Park Plate over six furlongs at Newmarket Racecourse and finished eighth of the fourteen runners behind Donovan.
[5] At the next Newmarket meeting two weeks later the colt finished second to Royal Star in the Criterion Stakes[6] and then started at odds of 8/1 for the Dewhurst Plate over seven furlongs.
[7] On his three-year-old debut, Enthusiast finished fourth behind Donovan, Mr Abingdon's Pioneer and Minthe in the £12,000 Prince of Wales's Stakes at Leicester on 6 April.
[8] On 1 May 1889, with Tom Cannon in the saddle, Enthusiast was one of nine colts to contest the 81st running of the 2000 Guineas over the Rowley Mile at Newmarket and started the 25/1 fourth choice in the betting.
[12] In the Epsom Derby on 5 June Cannon opted to partner Baird's more-fancied runner El Dorado leaving Calder to take the mount on Enthusiast.
[15] On 11 September Enthusiast, with Cannon in the saddle, started 100/6 thirdchoice in the betting behind Donovan and the highly regarded Northern colt Chittabob for the St Leger over 14+1⁄2 furlongs at Doncaster Racecourse.
[16] Ten days later the colt was dropped back in distance for the £12,000 Lancashire Plate over seven furlongs at Manchester Racecourse and finished outside the first five as Donovan won again.