I am pretty sure Martinez KOs him. Martinez's left hand is a fast, accurate and deadly weapon. Cotto can't avoid it and he can't survive it. Martinez is bigger, faster, has better stamina, skills and more heart.
No way Cotto fights Sergio because he knows what happens, he was able to go through Floyds punches to get inside, anyone really belives he could go through punches of Martinez? It gets stopped around 8 round.
At 154 this is a 50-50 fight. Cotto has the style to beat someone like Martinez because of his jab and the way Martinez keeps his hands down. Cotto would time him perfectly and score a UD.