Thomas was issued with a reinsman’s license in 1916 as increasing weight curtailed his career as a jockey. Renowned as a fierce competitor on the tiny WACA track, his first trotting winner was Wally M, trained by his father. Thomas rode or drove 265 winners between 1916 and 1949 before failing health forced a premature retirement from driving in races. He was Perth’s Leading driver in 1921 and 1942 and finished second in 1918, and third in 1924 and 1926. At 21 he became the youngest driver to ever win the Perth Reinsman’s Premiership in 1920/21. His 265 winners included four victories in the State’s premier race: the WA Pacing Cup.