He was the best British two-year-old of 1892 and went on to become sixth winner of the English Triple Crown[2] by winning the 2000 Guineas at Newmarket, The Derby and the St. Leger Stakes at Doncaster in the following year.

He was undefeated in his last two seasons, setting a world record for prize money[3] and gaining recognition from contemporary experts as one of the best horses seen in England up to that time.

[11] The win established Isinglass as one of the best juveniles of the season and he disputed favouritism for the following years Classics with the similarly undefeated Meddler, the winner of the Dewhurst Stakes.

[12] By February 17 Isinglass was clear favourite for both the 2000 Guineas (7/2) and the Derby (9/2),[13] although his odds lengthened slightly after a stable accident interrupted his training.

[14] A major obstacle to his success was removed when Meddler's owner, George "Abingdon" Baird, died in early 1893, thus canceling his colt's classic entries.

Instead of galloping the colt in the usual way, which would have risked injury, Jewitt and Machell brought him to fitness with a series of canters up and down Bury Hill.

He made steady progress to join the leaders just after half way and was sent through a gap along the rails to take a slight lead over Raeburn on the turn into the straight.

Two furlongs from the finish Isinglass swerved to the right and appeared to be struggling, allowing Raeburn to take the advantage and forcing Loates to use his whip and spurs on the favourite.

[20] Loates explained that the moment of concern early in the straight had been caused by Isinglass shying when he heard the roar of the huge crowd, and described him as running "as green as a two-year-old".

Isinglass, by contrast, had a series of training problems[28] forcing him to miss an intended run in the Hardwicke Stakes at Royal Ascot.

The race attracted a large crowd including the Prince of Wales (who supported Isinglass) and the Queen's cousin George, Duke of Cambridge (who favoured Ladas).

[32] The two Derby winners dominated the race in the closing stages but in spite of a "game pursuit" by Ladas, who got to within a neck of his rival at one point, Isinglass proved his superiority[33] and won by a length with the rest of the field, headed by Throstle, well beaten.

[34] Having won two of the "Ten Thousand Pounders", Isinglass attempted to win a third[35] in the Jockey Club Stakes over one and a quarter miles at Newmarket on 28 September.

The early stages of the race were marked by the erratic behaviour of the St Leger winner Throstle who bolted off the course despite the best efforts of her rider Mornington Cannon and embarked on "a tour of the country".

[46] Sent to Cheveley Park Stud near Newmarket for breeding duty, Isinglass sired three British Classic Race winners: Cherry Lass, Glass Doll, and Louvois.