Watch the fight between Buddy McGirt and Howard Davis Jr, and watch the tape made for the computer fight between Marciano and Ali. watch how marciano (they actually sparred a bunch of rounds for 'fight' footage) shades himself toward Ali's left at all times, keeping his head outside the jab. That gives him an angle for the right hand to the head or body when Ali tries to pivot out to his own left.
You'll be much better off if you can make him pivot into you, rather than around you.