As a member of the team, he was the first swimmer to compete at the National Open Short-Course Championship and make the finals.

[2] Antalfy first represented Australia in 2011, competing in the Para Pan Pacific and Arafura Games that year.

[7] As a twenty-five years old,[2] he was selected to represent Australia at the 2012 Summer Paralympics in swimming in the 100m and 50m freestyle, 100m butterfly and 100m backstroke S13 events.

[10] Competing at the 2013 IPC Swimming World Championships in Montreal, Quebec, Canada, he won a bronze medal in the Men's 100 m Butterfly S13.

[11] At the 2015 IPC Swimming World Championships, he won a bronze medal in the Men's 100 m Butterfly S13.