John houseman best supporting actor in the paper chase
He was in a couple things before Paper Chase including one of the before mentioned Welles shorts.
John Houseman had a small but pivotal role in Seven Days in May, nine years before The Paper Chase.
There has also been a tie in the Best Actor category: Fredric March in Dr. Jekyll and Mr. Hyde tied with Wallace Beery in The Champ in 1932.
Winning Debuts
Gale Sondergaard* for Anthony Adverse (1936)
Katina Paxinou* for For Whom the Bell Tolls (1943)
Mercedes McCambridge* for All the King’s Men (1949)
Shirley Booth for Come Back Little Sheba (1952)
Eva Marie Saint* for On the Waterfront (1954)
Jo Van Fleet* for East of Eden (1955)
Barbra Streisand for Funny Girl (1968)
Tatum O’Neal* for Paper Moon (1973)
Haing S. Ngor* for The Killing Fields (1984)
Marlee Matlin for Children of a Lesser God (1986)
Geoffrey Rush for Shine (1997)
- Supporting roles.
I would hesitate to include the two short films that Welles directed on 16mm in the 1930s. I recently saw the first, The Hearts of Age, and it reminded me of movies I used to make with my Super 8 camera when I was a teenager. The other was made as a filmed prologue for a stage production of the comedy Too Much Johnson.
Rush was in some things before Shine. One thing I remember was a film version of a play he was in. It was basically just the play filmed one night, but it was a movie.
Looking on IMDB Rush was in a lot of stuff pre-Shine.
Kevin Costner’s debut directorial release was Dances With Wolves.
Not really. He ad libbed his part, but did not write a script. It also won an Oscar due to him.
More (the writing awards are full of first-timers):
Ben Afflick, Matt Damon: Best Original Screenplay for “Good Will Hunting” (their first screenplay).
Pierre Boule: Shared Best Original Screenplay for “The Bridge on the River Kwai.” (even though he did no work on the screenplay).
Mario Puzo: Shared Best Adapted Screenplay for “The Godfather.”
William Saroyan: Best Adapted Screenplay for “The Human Comedy.”
D.M. Marshman: Shared Best Original Screenplay for “Sunset Boulevard.”
Steve Tesich: Best Original Screenplay for “Breaking Away.”
And, of course, Robert Rich. 
One of the problems with the IMDB: it doesn’t differentiate between student work and an actual film.
Forgot Emma Thompson: Best adapted screenplay for “Sense and Sensibility.”
It’s a Mitch Hedberg standup bit. I just happened to buy this CD on Tuesday.
“Alcoholism is the only disease you can get yelled at for having. ‘Dammit Otto, you’re an alcoholic.’ ‘Dammit Otto, you have lupus.’ One of those doesn’t sound right.”
Although he had done television work before, Ben Kingsley won a Best Actor Oscar for his first time big screen role in “Gandhi.”