After watching soldiers with a disability undertaking various sports, Pathirana was asked by his superiors if he wanted to join. He eventually took up para-athletics in 2010 and that year he was classified as a T46 athlete and entered his first international competition, the 2010 Asian Para Games. In 2012 Pathirana represented Sri Lanka at the Paralympics in London. He entered two events, the 200 metres and 400 metres sprints. In the 200 metres he failed to reach the finals, but in the 400 metres he finished third to claim his and Sri Lanka's first Paralympic medal.