I would put my money on any animal larger than a medium size dog. Even something as small as a raccoon would be pretty formidable I think. They have teeth, can be single minded in attacking, and are quick.
Why do cops shoot attacking dogs rather than clubbing them?
Let’s take wolverines for something on the small size. They are about the size of a medium dog yet have been known to kill bears.
Chimps are several times stronger than people, have arms, and are intelligent as non-humans go. I’d definitely would put my money on them.
Anything like lions, tigers, gorillas, etc are going to be a short and ugly contest for sure.