A martial arts enthusiast since his youth, Filipović started his professional career in 1996 as a kickboxer, following in the footsteps of his compatriot Branko Cikatić. Before turning pro, he had accumulated an amateur boxing record of 48–8 (31 KO's). He defeated Jérôme Le Banner in his debut, but after losing to Ernesto Hoost in his next match, he turned his attention back to boxing and his law enforcement career. He had success in both areas as a three-time national amateur boxing champion and later joined the Lučko Anti-Terrorist Unit where he served for six years until he was elected to the Croatian Parliament. Filipović took part in the 1997 World Amateur Boxing Championships, losing his first round match-up against Olympic medalist Alexei Lezin. At the time, he was working as a commando in the Croatian police anti-terrorist unit "Alpha" (stationed in Lučko near Zagreb), which earned him his nickname "Cro Cop". He fought several times early in his career under the nickname "Tigar" (Croatian for "tiger").