The bet paid off: Patterson not only helped solidify the format but also brought in co-hosts LL Cool J and Chrissy Teigen and go-to comedy director Beth McCarthy Miller to helm all 18 episodes. And though the franchise is so associated with The Tonight Show that it can be jarring to see it on a network that isn't NBC just as it would be to see Jimmy Kimmel's "Mean Tweets" or David Letterman's "Stupid Pet Tricks" airing anywhere but ABC and CBS, respectively producers note that it was Krasinski who created the bit. He and Merchant were road-tripping two years ago with Krasinski's wife, Emily Blunt, trying to drum up things for Krasinski to do during a Late Night appearance, when their silent takes on "No Diggity" and "All Night Long" morphed into an idea. (Fallon, careful not to upset his full-time employer, has used his show and Twitter to promote the Spike series but has kept a much lower profile when it comes to press.)
The third episode (Anne Hathaway vs Emily Blunt) of Lip Sync Battle is online BEFORE its Thursday night airing on Spike TV. The Anne Hathaway Wrecking Ball performance was the standout. Silly stuff, but perhaps weird enough to be worthy of a look:

Can select 720p from top corner (but all resolution choices have forced subtitles):

Max 480p version, but with no forced Subtitles: