In early 2015, the two-year-old colt was entered in the Tattersalls "breeze-up" sale (in which the horses are publicly galloped before being auctioned) and was bought for 30,000 guineas by Middleham Park Racing.
He then sustained similarly narrow defeats in maidens at Ayr and Carlisle in July before being beaten a short head by Receding Waves in a nursery (a handicap race for juveniles) at Haydock Park on 5 September.
Two weeks later the colt started at odds of 4/1 in an eighteen-runner nursery at Ayr in which he was ridden by the apprentice jockey Jack Garritty and recorded his first victory as he took the lead a furlong out and drew away to win "readily" by three and a quarter lengths.
[7] Six days after his win at York the colt was sent to France to contest the Group 2 Critérium de Maisons-Laffitte over 1200 metres on soft ground in which he was partnered by Alexis Badel.
He went off the 10.5/1 fifth choice in a seven-runner field which also included Smash Williams (Round Tower Stakes), Log Out Island (Two-Year-Old Trophy) and Yakaba (Prix d'Arenberg).
"[9] On his final run of the year Donjuan Triumphant returned to France and started favourite for the Critérium International over 1400 metres at Saint-Cloud Racecourse on 1 November, but never looked likely to win and finished fourth behind Johannes Vermeer, Stormy Antarctic and Attendu.
In the official European classification of two-year-olds for 2015, Donjuan Triumphant was given a rating of 115, nine pounds behind the top-ranked Air Force Blue, making him the tenth best juvenile of the season.
He was officially owned by Abudiencia Co Ltd until switching to Srivaddhanaprabha's King Power Racing in July of that and carried their blue and white colours for the rest of his track career.
A month later Donjuan Triumphant was ridden by P. J. McDonald in a minor race over seven furlongs at Haydock and recorded his first win since 2015 as he led from the start and came home one and a quarter lengths in front of his five opponents.
[14] On 21 October Donjuan Triumphant was moved back up to Group 1 class for the British Champions Sprint Stakes at Ascot but made little impact and finished eighth of the twelve runners behind Librisa Breeze.
On 10 November on soft ground at Doncaster Racecourse the horse was dropped to Listed class for the Wentworth Stakes, in which he was ridden by James Doyle and started the 2/1 favourite against thirteen opponents.
Advertise and One Master started joint-favourites while the other contenders included Hello Youmzain, Cape Byron, The Tin Man, Sands of Mali, Librisa Breeze, Brando and Mabs Cross.