Who would win in a sanctioned, professional MMA tournament between Sith Lord, Jedi Master and Samurai?
Assume Samurai would get the bye to the final implying Sith Lord and Jedi Master would fight first.
Jedi. 
I am picking Samurai via submission.
I feel they have upper hand in close combat. Have not seen much from Jedi/Sith in terms of takedown defense, submissions, striking etc.
However, the force is a powerful weapon and I'd like to see how this would play out.