If Mexico lose 1-0 or 2-0 to Portugal and Angola beat Iran 2-0 or 1-0 respectively, then Angola goes through and Mexico goes home.
I think I'm right in saying that at least. Mexico GD +2 at present and Angola -1...
I think you needs one goal larger differential unfortunately, due the number of goals scored by Mexico.
Unless Angola wins 4-3 or something :-)