The 30-year-old native of Imotski, a member of the AK Uriho club from Zagreb, won the medal with a 55.06-metre throw. The gold medal went to Jeremy Campbell of the United States, who made a toss of 60.22 metres, while the bronze went to Briton Dan Greaves, who scored 53.56 metres.
Katanušić's medal is the 22nd medal won by Croatian para-athletes at the Summer Paralympic Games and the third won at the Tokyo Paralympic Games.
Croatia now has a total of five gold, seven silver and ten bronze medals won at the Paralympic Games.