To that end, the two decide to sort things out with a gentleman's agreement: Whoever can beat the other senseless gets to keep distributing. This doesn't seem like the wisest choice for the Red Skull, considering the fact that he's a little bald Nazi and Kingpin is built like a dump truck. But then, the Red Skull is completely crackers, and in his defense, Kingpin doesn't really look like exercise is his thing.
So, in order to satisfy honor and make sure no one has any secret weapons, the two villains naturally have to take off their clothes, revealing that Kingpin is a boxers man and that the Red Skull has been walking around in a tiny black banana hammock all this time.
"H-How did he find out about my crippling foot fetish?!"
Remember, this is a comic book set in a world full of superpowers and fantastic technology -- if they wanted to, the writers could have easily made it so the villains simply scanned each other with X-rays to make sure they had no weapons. This clearly comes down to someone at Marvel really, really wanting to see Kingpin and the Red Skull punching the shit out of each other without clothes. The biggest blows, however, are verbal:
Yeah, Kingpin, that sounds way more convincing than, "I'm big-boned."
As much as he protests to being called fat, Kingpin's winning move is the same one every pudgy kid used in the fifth grade: pinning the other dude under his enormous gut until he gives up.
Captain America wisely waited for the greasy shitshow to be over before intervening.
And so, Kingpin effectively wins the fight and sees to it that if the people of America want to smoke meth, it's going to be his meth.
And speaking of meth ...