Maia can obviously win if he pulls off something quick on the ground or Fitch just sits in his guard.
But Fitch last fight proved he is still an elite WW.
Fitch is a blackbelt in some self defense art and a knowledgeable and strong grappler. He may be one of the harder guys to sub in the UFC. If anyone can it is Maia, but Maia has rolled with far less grapplers and couldn't sub them. Fitch should try to keep it standing anyway. Or the Fitch wall grind. I'm afraid it turns into a bad kickboxing match that Fitch will probably win.