At the 1960 Summer Paralympics, he competed in the Men's Precision Javelin, where he won a silver medal. He was a member of the Australian wheelchair basketball team at the 1962 Commonwealth Paraplegic Games in Perth. At the 1964 Summer Paralympics in Tokyo, Ponta competed in Class 2 Men's swimming in the 25 m breaststroke event, where he failed to medal. At those same games, he also competed in the class 2 Men's 25 m Freestyle Supine event, where he won a gold medal. He also competed in wheelchair fencing at the 1964 Games in the Eppee Team event, where he did not medal, and the Men's Foil Novice Individual, where he won a silver medal. At the 1968 Tel Aviv Games, he competed in the Class 2 Men's 25 m Breaststroke event, where he failed to medal. He also competed in the Men's 25 m Backstroke, where he won a bronze medal. He also competed in the 100 m Wheelchair race, the pentathlon complete, precision javelin open, slalom a, and in the wheelchair basketball team. He did not medal in any of these events.