Everybody can "lose" against Caesar Clown, he controls gas, he controls poison. Magellan was that dangerous not because he was a "high top tier whatever crap fans make up" nor because he was a beast of a fighter but because he's walking poison; take the Doku Doku from him and he'd be dead by now. Caesar negged five powerful fighters just by taking oxygen away; then Luffy was lucky he fought Magellan before because Caesar used deadly poisons against him; his satyrs negged the crew in the Sunny with gas, the Yeti Cool Brothers put three Straw Hats to sleep, shinokuni had everybody running for their lives and Jack destroyed the whole mink tribe with gas even though they had been fighting for five days without success.
Caesar Clown is weak as a fighter, but he's dangerous as hell if he takes you by surprise. One Piece characters are still human; it doesn't matter your made up power level if you're facing poison and gas.