Mayweather by arm-bar and I'm not even joking.
Mayweather Sr. from an interview with ESPN from 3 years ago...
"Ever since this talk of Floyd fighting Ronda has come up, he's been training his grappling game with the best in the world. Floyd got all the money, Floyd got all the fans, Floyd got whatever he wants. If Ronda or any other of these MMA people want a piece of The Champ, he'll be ready. Boxing or whatever, that weird shit where they are yanking each others arms back and forth, Floyd got that shit. He's ready to take on that Ronda chick or any other of these fools. UFC or Boxing, Floyd is ready."
He is the superior athlete, and if he didn't stop his "grappling game" training, and has been at it for 3 years, he stands a really good chance of submitting Conor.