From Hamilton, South Lanarkshire, Fleming first found success as an amateur, winning the East of Scotland title in 1919 and the ABA featherweight title in 1920, before turning professional later that year, fighting under the name Johnny Brown.
[1] Although lacking a knockout punch, Brown's speed and skill brought him considerable success.
[7][8] In September 1924 Brown lost his Scottish title to fellow Hamiltonian Tommy Milligan.
[10] In October 1925 Brown fought Harry Mason for the British welterweight title vacated by Milligan, and took a points decision to become champion.
[14] McCall won on points, and beat Brown again in March 1929 when the two fought for the title again, the first Scottish Area title fought under the auspices of the British Boxing Board of Control and the last major fight to be held in Britain over 20 rounds.