Kemboy duly delivered on Irish debut at Limerick, winning a modest maiden hurdle as the 8/13 favourite under Ruby Walsh, only being nudged out towards the line.
He would then be stepped up in class in January 2017, finishing second behind favoured stablemate Let’s Dance in a Leopardstown Grade 2 novice hurdle.
After unplaced runs at Cheltenham and Punchestown festivals, he was immediately sent over the bigger obstacles, being beaten on chase debut by Gordon Elliott’s Sutton Place at Fairyhouse in January 2018 but got his head in front again at the same track later that month.
Kemboy would struggle at Cheltenham in Graded company, but after falling in the Irish Grand National at Fairyhouse he bounced back with a convincing Grade 3 novice chase success at Limerick in April 2018.
He would again land another significant gamble at the Punchestown Festival later that month, being the subject of market support to go off the 11/4 favourite in a competitive Grade A novice handicap. Off a lenient mark of 147, Kemboy travelled strongly into the race under Paul Townend and swept clear to win by an eased-down five lengths. It would be his last run at handicap level.
After a summer break, he kicked off the 2018/19 campaign with Grade 2 victory in open class for the first time, beating Gigginstown duo Alpha Des Obeaux and A Toi Phil in the Clonmel Oil Chase.
Arguably his best performance to date came in the Grade 1 Savills Chase at Leopardstown’s Christmas Festival on December 28, 2018.
David Mullins took the ride with stable jockey Ruby Walsh on Bellshill and Mullins took up the running with a circuit to run, deeming the gallop not strong enough for his mount. That proved to be a masterstroke.
The enterprising Mullins made it a true test of stamina and despite the chasing pack closing in at the second last, Kemboy (8/1) had enough in the tank to pull away and win in the end by seven-and-a-half lengths from Monalee and Road To Respect.
That victory booked Kemboy’s spot in the Blue Riband event of the season, the Cheltenham Gold Cup which took place at Prestbury Park on Friday March 15, 2019. However, anticipation and expectation soon turned into heartache for the Supreme Racing team as Kemboy buckled on landing at the first, unshipping David Mullins in the process.
Willie Mullins would win the race and his maiden Cheltenham Gold Cup with Al Boum Photo, who would lock horns again with his stablemate at the Punchestown Festival.
In the interim, Kemboy claimed a second Grade 1 prize at Aintree, taking the Betway Bowl in emphatic fashion with a well-judged ride from Ruby Walsh. Having been given a soft lead out in front, Walsh and Kemboy galloped his opposition - including Betfair Chase winner Bristol De Mai and King George VI Chase winner Clan Des Obeaux - into the ground and quickened clear in the straight to win by nine lengths.
Mullins’ two staying heavyweights would clash in the Irish season finale, the Punchestown Gold Cup. It would prove to be a poignant success for Ruby Walsh and Kemboy who was keen early on, having been challenged for the lead by Brian Ellison’s Definitly Red.
However, he saw off that threat and had enough left in the tank to see off Al Boum Photo and Paul Townend in what was a titanic tussle all the way up the Punchestown straight.
Ruby Walsh would wave to the Punchestown crowd as he crossed the finish line as a final goodbye, announcing his immediate retirement minutes after the race to RTE Sport and Racing TV.