Blascheck was successful at junior level before his senior career, having won the bronze medal at the 1999 European Athletics Junior Championships and the silver medal at the 2000 World Junior Championships in Athletics. His senior breakthrough occurred in 2005, when he was the German champion indoors and outdoors and took a silver medal at the 2005 European Cup. Later that year he reached the semi-finals at the 2005 World Athletics Championships. He won the silver medal in the 110 metres hurdles at the 2006 European Athletics Championships in Gothenburg. He also competed internationally over 60 metres hurdles and reached the event final at both the 2005 European Athletics Indoor Championships and the 2006 IAAF World Indoor Championships.