Jason Ong Koon Yew, son of Mr Ong Boon Hin of Warplan Racing Stable, first helped his father out in his business after serving his National Service, but grew to share his father’s passion for racing, deciding in 2011 to study a one-year course in Horse Business Management at Marcus Oldham College in Geelong, Australia.

Upon graduation, Ong worked as a track rider for trainers Peter Moody and John Sadler in Melbourne in 2012 and 2013 before returning to Singapore in 2013 to join New Zealand trainer Mark Walker, where the Warplan Racing Stable-owned Singapore champion galloper War Affair would kick-start his career, as a senior track rider and stable supervisor.

The following year, Ong and War Affair moved over to trainer Alwin Tan, where both enjoyed their highest accolades during a multiple-Group-winning spree that included five at Group 1 level with the 2015 Lion City Cup the career highlight.

In 2016, War Affair and Ong joined New Zealand trainer Bruce Marsh, where Ong became assistant-trainer for the next three years, before officially being granted his trainer’s licence and taking over the retired-Marsh’s string of horses in September 2019.