Ivančić became the top Yugoslav shot putter in the early to mid-1970s. He won the Yugoslav championship seven times (1970–1975, 1977) and improved the national record six times. He won a gold medal in shot put in the 1975 Mediterranean Games, bronze in 1979, and two bronze medals in the 1980 European Athletics Indoor Championships and the 1983 European Athletics Indoor Championships. In addition, he represented Yugoslavia in the 1972 and 1976 Summer Olympic Games and in the 1983 World Championships in Athletics in Helsinki, placing 19th, 16th and 12th respectively. His appearance in the shot put final in Helsinki, at the age of 45 years 244 days, makes Ivančić the oldest ever World Championships competitor in shot put, as well as the oldest ever World Championships finalist in any event.