He defeated Hasan Gul in the semi-finals and then Eyup Kuscu in the final to become the Heavyweight Champion of Turkey.

He made his debut with the K-1 promotion in August 2007 at the K-1 World Grand Prix 2007 in Hong Kong, where he defeated South Korean ssireum fighter Kim Dong-Wook in a reserve match for the 8-man Grand Prix taking part on that night.

On November 2, 2007, Deniz took part in the Grand Prix at K-1 Fighting Network Turkey 2007 but was defeated by Brazil's Vitor Miranda at the quarter-final stage.

On June 11, 2011, he made his It's Showtime debut against the Romanian Daniel Ghiță in the main event at BFN Group presents: It's Showtime Warsaw and lost via knockout in the second round due to a body shot.

On September 16, 2010, he married Nurhayat Hiçyakmazer, a Turkish world and European champion in several martial arts disciplines.