Fritz is a relatively short goalkeeper (only 1.88 m) who began playing major-league handball with SC Magdeburg. He moved to THW Kiel in 2001 and has been a member of the Men's German National Handball team since 2002. The German team took second place in the European championships in Sweden that year and another second place in the world championships 2003 in Portugal. In 2004 he participated in the teams success in Slovenia, where they took the European Championships. In 2004 in Athens he played with the team to another second place.
The opening game of the 2007 Men's Handball World Cup was his 200th game on the national team. He played a great championship, became Most Valuable Player in several games and was nominated for the All Star Team.