Competing for Ukraine, Prokopenko was the Canadian canoe C-1 500 m silver medallist at the 2002 Junior European Championships in Zagreb. Competing in two Summer Olympics also for Ukraine, Prokopenko earned his best finish of eighth in the C-2 500 m event at Beijing in 2008. He and team-mate Serhiy Bezuhliy finished fourth for Azerbaijan in the men"s C-2 1000 m at the 2012 Summer Olympics.
He won a bronze medal in the C-2 1000 m event at the 2006 International Coach Federation Canoe Sprint World Championships in Szeged. Prokopenko moved to Azerbaijan after the 2008 Summer Olympics and won two medals for his new nation at the 2009 International Coach Federation Canoe Sprint World Championships in Dartmouth, Nova Scotia with a silver in the C-2 1000 m and a bronze in the C-2 500 m events. He also won a silver in the C-2 500 m event at the 2010 championships.
