Despite a high-profile defeat to O'Brien in 1894, St. John continued to fight, but a disastrous contest in which as a cornerman a boxer died at an unsanctioned match saw his career put in jeopardy.
After joining the British Army, he was posted to South Africa where he fought in the Second Boer World and died in heroic circumstances at the Battle of Belmont.
A coal miner by occupation, St. John supplemented his wage through illegal boxing matches and fighting at local fairgrounds.
[2] Not long after the meeting with O'Brien the two men travelled to London where they spent some time at Bob Habbajim's Boxing School, though a lack of credible opponents led to St. John returning to Wales.
[3] With O'Brien suffering from ill-health and James already beaten, St. John laid claim to the title of Welsh heavyweight champion.
At first there was interest for the fight to be held at the Kennington Club in London, but the time table suggested did not favour St. John and the bout was arranged for the People's Park in Pontypridd.
[8] Eventually interest was shown by the National Sporting Club in London which offered a purse of £50 to host the contest between St. John and O'Brien.
[9][10] After the fight St. John tried to force a rematch with O'Brien and also put out challenges to some of England's best fighters, including Jem Smith, but none were accepted.
During authorised leave, St. John was asked to take up the position of cornerman in a fight at a slaughterhouse in Aberdare between David Rees and Thomas Robert Edwards.
As the crowd fled, St. John remained behind in an attempt to revive the stricken Rees, but the fighter died before medical assistance arrived.
[12] His boxing career was saved when a call came out for a sparring partner for Australian heavyweight champion Peter Jackson who had recently arrived in London.