What is the greatest one scene performance in cinema history that completely stole the movie?

[u/culebrero]

I am talking about an actor who gets less than 5 or 10 minutes of total screen time, has zero setup, walks into a movie, absolutely electrifies the room, and leaves every single main A list actor standing in their shadow.When the credits roll, you aren't even thinking about the main plot anymore you're just thinking about those few minutes.The gold standard for me is Alec Baldwin in Glengarry Glen Ross. He shows up for exactly one scene, delivers the brutal, iconic seven minute Always Be Closing monologue to a room full of legendary actors, and walks out. He isn't seen for the rest of the film, yet his scene completely defines the entire legacy of that movie.Another wild one is Ned Beatty in Network. He gets one sequence at the boardroom table to deliver a terrifying speech about the corporate world, entirely shifting the tone of the film, and walks away with an Oscar nomination for it.Who is that one actor for you? To keep the mods happy and follow the sub rules, don't just name-drop the movie give me the exact breakdown of the scene, why it worked so well, and how it completely outclassed the rest of the script.

[u/BrandyeB]

I was going to say the trailer scene in True Romance!

[u/OneYouDidntThinkOf → u/BrandyeB]

and in Annie Hall. Nice screen time