Diaz has a very shaky chin, horrible defense, a brawling style, and he's been down early multiple times in his career. Even a less explosive Pacquiao at 135 should blow him out easily. Go ahead and do whatever you want.
Wouldn't be surprised if Pac blows him out the 1st round...He ha sthe capability, its just a case of wether he chooses to. Usually Pac uses the 1st round to test the waters, but if Diaz comes there to brawl, Pac goes all out 1st round, logic dictates its a 1st round KO... Edit: Wow, its my 4000th post!