Fallon: Williams the 'Muhammad Ali of comedy'

Before getting into Tuesday night's show, Jimmy Fallon took a few minutes to remember Robin Williams. The Tonight Show host choked up a bit as he said, "If you never saw the guy's stand-up, you need to YouTube it right now. He was amazing. He was funny. He was fast. He would weave in and out of characters …" And rather than try to explain it, Fallon gave a pretty convincing impression of the manic comic.

"You'd watch him," Fallon said as he climbed back into his chair, "and you'd cry laughing. And you'd think, 'I'm never going to see anyone like this human, ever. His brain was always thinking 10 steps ahead of what he was saying. He was like the Muhammad Ali of comedy."

After showing a clip of Williams running around Johnny Carson's stage in leather pants in his very first Tonight Show appearance in 1981 (he would visit 33 times in all), Fallon climbed up on his desk for a Dead Poets salute, calling out, "O Captain, my Captain, you will be missed."

Check out the video below.