Federer, Murray, Delpo..all these guys can beat Djokovic there. Also interestingly Djokovic has reached 4 cincy finals ( 2 against fed and 2 against Murray) and has not won a SET! although he retired in the 2011 match after the first.
"King slayer is a mere executioner, and is not as great as the one who he slayed."- Chico