Aside from simply being blessed with a “good chin” or the ability to take a punch, the absolute best thing you can do to protect yourself against “getting rocked” is to strengthen your neck muscles.
A perfect example of this is “Iron Mike” Tyson, who by the age of eighteen possessed a neck that was over 20 inches around. This undoubtedly helped him walk through some bombs and get out of most fights unscathed early in his career.
There are plenty of harmful ways to increase your neck strength, just as there are healthy ways. We encourage you to educate yourself on safe exercises. You never want to put undue pressure on your vertebrae, but you do want to use weighted movements that will help reduce rotational force when you take a shot.