monzon, big! i respect everything that fullmer accomplished in his career but he looks terrible on film to me. i understand he was a very, very good fighter but he's hard for me to watch.
Gene could take a few frames early when Monzon was typically most sloppy, looking to find his range and timing before opening up his arsenal and mixing left hooks and right uppercuts in with his bread-and-butter 1-2. After that, pretty long night. Fullmer was great, and excellent at disrupting rhythm but not at a level high enough to take Carlos out of his game. I imagine he would've been dealt with far easier by early 50s Robinson as well.
Gene would ultimately be tied up and rendered ineffective. Monzon would be too hard for him to reach.
Monzon would jab Gene's big noggin' all night, although neither fighter is getting knocked down or out. Monzon by UD.