Brian Williams -- Bumped to Cable ... Lester Holt the Winner

Brian Williams has officially lost his coveted position as anchor of NBC Nightly News, and Lester Holt is his successor.

Williams -- who is nearing the end of his 6 month suspension for lying about being shot at in a helicopter -- was demoted to anchor of the struggling MSNBC cable channel, this according to NBC's official announcement.

And this hurts ... NBC says, "Williams will serve as a breaking news anchor for NBC News live special reports when Holt is not available."

Williams will assume his new role when he comes back in August.