At the 2000 World Junior Championships Gatzka won a silver medal in 4x400 m relay with Christian Duma, Steffen Hönig and Bastian Swillims. Gatzka travelled to the 2004 Summer Olympics as a reserve team member, but did not make an Olympic start. At the 2005 European Indoor Championships he won a bronze medal in 400 m and came in fourth with the German 4x400 m relay team.