Got to this a couple days late, but here we go: Best Director, 1948.
Actually, before we get to the nominees - did you know this was also the first year that the Directors Guild of America gave out competitive awards? What was going on that everyone suddenly wanted their own trophies?
There were only four nominees that first year, only half of whom were also nominated at the 21st Academy Awards: Anatole Litvak for The Snake Pit and Fred Zinnemann for The Search. The other two were Howard Hawks for Red River and Joseph L. Mankiewicz for A Letter to Three Wives...a 1949 film. Mankiewicz would repeat his win at the 22nd Academy Awards, while the winner of the 1948 Oscar wasn't even nominated at the DGA Awards. Go figure!
Here are Oscar's nominees: