Don't wrestle him. You'll lose unless that is your profession.
Stick and move and repeat. He lunges at you, take a step back and pop in the nose/throat. IF he takes you into a head lock or similar, hit repeatedly in nuts... that takes the fight out of anyone.
If he goes down, don't stop, take the advantage and pound that head a few more times. You only quit when its apparent he's done.
Remember his eyes, throat, nuts are the best weak spots to take an advantage.