On his first run over obstacles he won "easily" at Wincanton on 15 January, taking the lead approaching the final hurdle and drawing away to win by nine lengths.

[8] Nine days later the gelding was stepped up in class for the Grade 2 Classic Novices' Hurdle at Cheltenham Racecourse and finished tailed-off in seventh place behind the Alan King-trained Ordo Ab Chao.

Having been ridden by an amateur jockey in his previous starts, Thistlecrack was partnered by the leading professional Ruby Walsh when he ran at Ascot in 14 February.

Starting at odds of 100/30 he came from last place to join the leaders at the final flight of hurdles and "stormed clear" on the run-in to win by three and three quarter lengths.

Ridden for the first time by Tom Scudamore he started a 25/1 outsider in a sixteen-runner field headed by the Willie Mullins-trained Roi des Francs.

On his first appearance of the new season, Thistlecrack was one of five horses to contest the Grade 2 Long Distance Hurdle over three miles at Newbury Racecourse on 28 November.

[13] Three weeks later he started favourite for the Grade 1 Long Walk Hurdle at Ascot, with his main opposition appearing to come from Reve de Sivola (winner of the race for the last three years) and Saphir du Rheu (Mildmay Novices' Chase).

[14] Tizzard, who had moved his horses to a new training facility away from his dairy farm commented "now I’ve got a racing yard without cows in sight, it's lovely".

[18] At Aintree on 9 April Thistlecrack started 2/7 favourite for the Liverpool Stayers' Hurdle against four opponents were headed by the Nicky Henderson-trained Different Gravey and the RSA Chase runner-up Shaneshill.

[19] Rather than continue to campaign the horse against other novices, Tizzard opted to match Thistlecrack against more seasoned steeplechasers in the King George VI Chase at Kempton Park Racecourse on 26 December.

[20] On 28 January Thistlecrack started 4/9 favourite for the Cotswold Chase at Cheltenham but sustained his first defeat in a steeplechase as he was beaten a short-head by the ill-fated Many Clouds who collapsed and died after the race.

Despite his defeat he maintained his position as favourite for the Cheltenham Gold Cup but after sustaining a tendon injury in February it was announced that he would miss the rest of the season.

After a ten-month absence Thistlecrack returned in the Long Distance Hurdle at Newbury on 1 December 2017 when he started the 11/10 favourite but came home fifth of the six runners behind the 40/1 outsider Beer Goggles.

"[21] Thistlecrack made his comeback in a strong edition of the Lancashire Chase at Haydock Park on 24 November 2018 and ran well to take third place behind Bristol de Mai and Native River with Clan des Obeaux and Might Bite in fourth and fifth.

In the King George VI Chase at Kempton on Boxing Day he took the lead at the fourth last but was overtaken by Clan des Obeaux at the final fence and finished second, beaten a length and a half by the winner.

On 29 November 2019 Thistlecrack started second favourite for the Long Distance Hurdle at Newbury and finished second of the five runners, beaten a length by the winner Paisley Park.