It has happened before, and quite frequently. They might not be the lead but they leave an impression. Short roles have even won. Beatrice Straight won for her 5 min, two scenes short role in Network. Judi Dench won for her 8 min short role in Shakespeare in Love. As for nominations we have Viola Davis who got her first nomination for a short but memorable scene in Doubt. Sylvia Miles got nominated for a very brief scene in Midnight Cowboy. Michelle Williams would join that exclusive club of short but memorable performances.