How did he do that?

Just a very short peek at a magician here on Japanese TV. He's an older gentleman, but does appear fairly often, and I've got to admit, I enjoy his appearances. I think most of the ones I've seen follow a similar pattern.
( An example of the pattern )

Somehow that "I'm a joke of a magician" followed by a reasonably good trick that he doesn't even notice tickles my funnybone.