Amid Brian Williams Controversy, ABC Surges Past NBC on Friday

After winning each of the first four days of last week, NBC's "Nightly News with Brian Williams" took a tumble on Friday and was surpassed by ABC's "World News Tonight with David Muir," according to preliminary affiliate-based estimates from Nielsen. All three evening newscasts typically see their lowest ratings on Fridays due to the start of the weekend, but the declines were significantly larger for the NBC program than its rivals.

NBC News President Deborah Turness on Friday said the network was conducting an investigation into the controversy surrounding Williams, whose claims that he was on a helicopter in Iraq in 2003 that was struck by a rocket-propelled grenade have been challenged by crew members of the aircraft. Williams on Saturday told NBC News staff members in a memo that would be stepping aside "for several days," with weekend anchor Lester Holt taking over the newscast starting tonight.

Looking at Friday's preliminary numbers, ABC's "World News" dominated in the key news demo of adults 25-54 with 2.008 million viewers, followed by NBC (1.701 million) and CBS (1.518 million). ABC and CBS were down about 15% from their Monday-Thursday averages, while NBC was off by about 35%.

And in total viewers, ABC (8.461 million) beat out NBC (7.979 million) for its only nightly victory of the week, with the former down 10% from its Monday-Thursday average and the latter down 20%.

While NBC has been the consistent winner in total viewers, the evening news race between NBC and ABC has been very close in adults 25-54.

ABC's "World News," under new anchor David Muir, edged out NBC in adults 25-54 in November for its first demo victory in the sweeps month in 18 years. "Nightly News" has won every week in 2015, but by an average margin of just 7%.