This is the greatest question ever.
If the chimp lows what is going down, it wins every time, training or not. Chimps are just so much faster and more powerful than a human that it wouldn't be a contest. Now, a trained fighter an with a knife could sink it into the chimp's ribs or something as the chimp bites his face off, but a draw is the best a human can ask for here.
Now, a human can always just slit a chimp's throat before it knows what is happening. But that isn't really a fight, is it?
There used to be a show on TV called Man vs Beast. It featured contests between humans and animals. Often the animal in question would a chip, and they always had the same problem; the chimp simply didn't give a crap, and did whatever it wanted. A contest in who can climb a tree faster? The chimp casually saunters up while the human climbs as fast as possible. Who can hang on monkey bars longer? The chimp gets bored and starts fooling around up there, doing flips and hanging upside down, while the human stays hanging by his hands. Who can throw a ball the farthest? The chimp eats the ball.