I'd favour Khan but at 135 he was alot more vulnerable to being caught than he is now as he wasn't using his attributes anywhere near as well as he does at 140. Plus I think he was really struggling to keep down to the lightweight limit. Diaz isn't a massive puncher but he has enough pop to hurt the lightweight Khan, and is relentless enough to get to him late. I think Amir pulls out a UD after rough spells late on.