I gotta fight a fat guy in a few hours. Goodbye. UPDATE: Never underestimate fat guys.

[dr3b]

Leg kicks, watch his punches and movements for openings, use his weight against him if possible.
You don't want to hit him square on the cheek, but a glancing blow off the chin... put him out if you do it right.

That said fighting doesn't solve anything, but if he initiated it what can you do.