Fallon has had a lot of fun with the straight-laced Williams, who deadpans the national news every night.
In the latest hilarious mash up, Fallon has Williams performing the Warren G’s classic “Regulate.”
On Wednesday (June 5), Fallon aired another edited video of Williams rapping Snoop Dogg’s version of Dr. Dre’s 1992 hit “Nuthin’ but a G Thang.”
See Williams’ latest rap and his mashup from Wednesday night below. You can catch him at his day job on the NBC Nightly News most weeknights. And follow TheImproper on Twitter to keep up with all the hottest comedy from television.