Has pacquiao faced any good southpaws?

Pacquiao has smashed all the southpaws that he has fought, but most haven't exactly been world class. There's a couple of Asian guys like Fahsang 3K Battery and Rakkiatgym who have decent records but it's hard to know how much they're worth. (For the record, both of those guys have challenged for the IBF super bantam title but never managed to win it, and they both got KO'd hard by Pac). Also, those fights were in 2002 and 2004, which might as well be another lifetime.

So you're left with Diaz, and the fact that a couple of Pac's opponents like Barrera and Cotto are natural southpaws converted to an orthodox stance. Naturally that doesn't mean much because they weren't fighting him out of the southpaw stance.

So, Pac has been a complete menace against southpaws, and he seems to relish it whenever he fights one, but none have been anywhere near elite level.