Marvel Two-In-One Annual #4, written by Frank Miller.
There are so many reasons to love this comic, Purple Man being only one of them. Others are: Moon Knight and Daredevil.
This is actually the second time they met. The first was in Moon Knight #13.
Moon Knight is out of character in this issue, as he is any time anyone other than Doug Moench wrote him. At least that was true for the entire decade of the 1980s.