I don't know ... a chimpanzee knows how to fight lol. But in terms of raw power ( power level ) I would say that the Chimpanzee has more. They are extremely strong.
Brock Lesnar is going to die. Chimpanzee is stronger, faster, and can fight long distance with it's feces. If Brock gets hit by them or gets a whiff of it than he's done.
Being realistic here...
If not claws or fangs are mixed, AND the chimp has been cleaned nice.
Brock still has a VERY good chance. He's most likely smarter, can plan attacks, and has technique.
Though its true, the chimp could be stronger.
Well I think a chimpanzee is less than 100 kg whilst brock is way above 220 lbs. Moreover Brock has the edge in martial arts. Its not like the chimpanzee would do a roundhouse kick or something. On the other hand the chimpanzee has the "bloodlust" and the ability to resist pain way better than brock would.
If the chimpanzee could kick or punch Brock in the guts, the monkey wins. You know that is Brock's achilles point, via diverculitis