Jentsch is a three-time German champion, winning the 8-ball national championship in 2009 and 2012, and 9-ball in 2010. At the 2011 European Pool Championships, Jentsch won his first European championship in 8-ball, through a final victory over Ralf Souquet. The following season, at the 2012 European Pool Championships he won the event for a second time, winning the 10-Ball event through an 8–5 win over Stephan Cohen.