I have a character who, for most of his life, fought physically against various supernatural beings; he has lots of experience and training in that arena. However, he was deaged. Time passed, now he's physically about 7 and as in-shape as a 7-year-old can be. With his body and experience, is it possible for him to take down (knock out or force to surrender, not kill) an Air Force officer (Major or Lt. Colonel, to be specific) in a fight? If it's not possible, I can always have his ambush succeed completely rather than turning into a fight, but it wants to be written with a fight.
I googled "children self defense", but the results aren't really the kind of self-defense he would be using.