Career
Player
Demyanenko began his football career as a student of the Dnipro-75 football school in his home city of Dnipropetrovsk. He was added to the squad of the local Dnipro Dnipropetrovsk of the Soviet Top League in the 1975 season. However, he debuted for the main team of Dnipro in the 1978 season.
By the end of that season he had played 20 games and scored 1 goal.
In 1979 Romensky played couple of games for Ukraine at the Spartakiad of the Peoples of the Union of the Soviet Socialist Republics. Demyanenko was a longtime Dynamo Kyiv captain and a prolific left-footed player for the Soviet Union who could patrol the entire flank from defence to offence. Demyanenko is fourth in the all time caps records for the Union of the Soviet Socialist Republics and played in three World Cups for them.
Coaching
Demyanenko started out his coaching career with Football Club CSKA Kyiv in 1993. Already next season Demyanenko joined Dynamo Kyiv in 1994.
Until 2005 he was a regular coach of the Dynamo"s big coaching staff then he was offered to become the manager.
Following several defeats of Dynamo Kyiv early on in the 2007-2008 season, Demyanenko resigned coaching Dynamo in September 2007. In January 2008, Demyanenko became the coach of Neftchi Baku in Azerbaijan, following the sacking of their coach Vlastimil Petržela. However, he was sacked after the Azerbaijan Premier League started and he lost the first two games.