IIRC This is from the 40’s or 50’s. A human and alien whose races are at war both crash land on a barren planet, and the human must triumph over an alien leader who is much more physically and mentally advanced than he is, and he uses Freudian principles and hypnotism to win the day.
Does this ring any bells?
Arena comes to mind, tho not quite those details.
Neither of those. The alien leader is incredibly arrogant and has mental broadcast powers which can take control of man if he sleeps, but the alien is injured and cannot leave his ship so he keeps trying to compel the human to come to him him. IIRC the man has to try and keep from sleeping.
Oh! Larry Niven. 1966. World of Ptaavs. And if this isn’t it, I’ll give up for today. 
Thank’s for suggestions. It’s a great story, but not it.
Sounds like A E Van Vogt’s villians, “The Rull.”
That’s it! Thanks.