Stephens competed in three events in the 2008 Summer Paralympics, finishing 11th in discus, 8th in shot put and 4th in the javelin. In 2011, Stephens won the gold at the Paralympic Athletics World Championships in New Zealand, recording a lifetime best of 39.11 metres in the javelin. He followed this up by recording a world record, at the Czech Athletics Open in Olomouc, in the men's F57 javelin with a distance of 41.37 metres.