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.

Stay low.. his only chance against you is grappeling you, staying out of a reach is a bad advice cause he'll always get into your reach no matter what. You get distracted, another kid, boobies, spit in you eyes etc.. so be prepared that he will get up close to you, his first few punches won't affect you because of your adrenaline.. (exept if he punches you just below the ribs punching your air out and right besides the ear)

now the big trick here is to get him tripping over, so you will have a 2 to 3 sec to deliver the final blow, don't be bother by hitting a guy while he's down.. only losers will complain about that. By staying low, your point of gravity is lower then his making the chance higher to use yourself as leverage to trip him (or a part of him) over you. use your shoulder, your leg, your back to trip him.. when he's down kick him a few times where it hurts... if he gets up repeat the process.. if he cries for his mommy.. you win some cool points..

ow an never NEVER underestimate the speed of a fat guy.. cause when you hear an icecream truck and go out.. the fat guy is always the first in line..

Drop a double bacon cheeseburger on the floor. The guy will jump after it and when he does, that's when you kick him in the face and you win!! For an added bonus, you bring a dog to eat the burger so when the guy is conscious he will become suicidal.

Will you update us after the fight?

Possibly get someone to film it?

Train with Punch-Out!!.

That tells me he's not really all that fat and is actually pretty strong. If you can't keep away from being wrestled down or punched or take a solid punch... well then.

Honour is for losers and dead people. Poison his food or something.

I don't think he can use the internet from the hospital after the fat kid breaks his arms..