Just a week after picking up his Best Supporting Actor Golden Globe for his fantastic turn in Three Billboards Outside Ebbing, Missouri, Rockwell is hosting Saturday Night Live and has managed to leave his mark.
During a sketch called The Science Room With Mister Science, Rockwell plays a friendly scientist who is driven slowly mad by two incredibly dense (and not in a scientific way) students.
Over the course of the video, we see Mister Science lose his temper more and more, until Rockwell gets so into it that he ends up shouting "How can you be this f*cking stupid?!"
You can see him break character for just a split second when he realises what he's done (which was apparently bleeped for the LA broadcast, but not for the New York one), but quickly gets back into character, once again screaming at the kids in the room.
Elsewhere on the show, he happily breaks out a few dancing moves, which he is known and loved for in his cinema career. See: Confessions Of A Dangerous Mind, Charlie's Angels, Moon, Iron Man 2, The Hitchhiker's Guide To The Galaxy.
Here, he makes it a part of his opening monologue, when he realises that he will no longer be a character actor, and that he is about to ascend to leading man status.
Oh, and in case you missed it, here are our chats with the man himself when we had the opportunity to sit down with him for a few minutes to discuss his new movie:
