My favorite fight is Kirk/Khan from "Space Seed." In order to get his ship back, with no access to his technology, he just beats a guy's ass with a pipe.
I was just watching STID the other day, and CumberKhan is depicted as much stronger than the original, despite being the same character from the same origin (since his cryostasis predates the timeline change). Though MontalKhan still has that phaser-busting feat.
Or it could be that PineKirk isn't as physically strong as ShatnerKirk either. Hm.
But it's interesting to note that QuintoSpock defeated Khan with, among other things, a heavy metal brace. Maybe Spock Prime told him to do that because Shatner Kirk beat him that way, too?