Fast National ratings for Thursday, February 26, 2015.

The two-hour season finale of "How To Get Away With Murder" did big numbers for ABC on Thursday, helping the network easily win the night among young viewers. But even though "Murder" more-than-doubled the "Victoria's Secret Swim Special," a new "Big Bang Theory" still allowed CBS win Thursday overall.

While CBS discovered the limits of the Victoria's Secret brand -- the star-studded annual Fashion Show special is a reliable annual smash -- the network saw respectable second week retention for "The Odd Couple" and an OK time period premiere for "Mom," which held onto all of its "Big Bang Theory" repeat lead-in. 

Over on NBC, the news was mixed, with "The Blacklist" getting a tiny bump in its first airing without "Scandal" competition, but both "The Slap" and "Allegiance" remained untenably low.

FOX's "American Idol" added a few viewers overall and was flat in the key demo and "Backstrom" did the same.

On to the numbers...

Among adults 18-49, ABC averaged a 2.6 rating for Thursday night, tops in the key demographic. CBS was second with a 2.2 key demo rating, far ahead of the 1.5 key demo rating for FOX's night. NBC was fourth with a 1.1 key demo rating, followed by The CW's 0.2 key demo rating.

Overall, though, CBS averaged an estimated 8.74 million viewers and a 5.5 rating/9 share, compared to the 8.47 million viewers and 5.6/9 averaged by ABC for Thursday night. FOX's 6.52 million viewers and 3.9/5 took third, followed by NBC's 5.03 million viewers and 3.2/5. The CW averaged a 0.5/1 and 715,000 viewers.

8 p.m. - CBS started primetime in first with "The Big Bang Theory" (16.33 million and a 4.5 key demo) and "The Odd Couple" (11.04 million and a 2.8 key demo, in like with recent "Mom" retentions). FOX's "American Idol" was second with 9.27 million viewers and third with a 2.1 rating among adults 18-49, compared to the 7.47 million viewers and 2.2 key demo rating for ABC's "Grey's Anatomy." NBC's "The Slap" averaged 3.62 million viewers and a 0.7 key demo rating, still far superior to the 761,000 viewers and 0.3 key demo rating for The CW's "Vampire Diaries" repeat.

9 p.m. - ABC won the 9 p.m. hour with 8.67 million viewers a 2.7 rating among adults 18-49 for the start of the "How To Get Away With Murder" finale. CBS was second with a "Big Bang Theory" repeat (8.88 million and a 2.1 key demo) and a new "Mom" (8.155 million and a 2.1 key demo). NBC's "The Blacklist" was third with 7.85 million and a 1.8 key demo rating, easily topping the 3.76 million viewers and 0.9 key demo rating for FOX's "Backstrom." The CW's "Supernatural" repeat averaged 669,000 viewers and a 0.2 key demo rating.

10 p.m. - "How To Get Away With Murder" closed with 9.27 million viewers and a 2.9 rating among adults 18-49, dominating the 10 p.m. hour. CBS' "Victoria's Secret Swim Special" was second with 4.02 million viewers and a 1.0 key demo rating, bad numbers but still better than the 3.61 million viewers and 0.8 key demo rating for NBC's "Allegiance."

All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.

A long-time member of the TCA Board and a longer-time blogger of "American Idol," Dan Fienberg writes about TV, except for when he writes about movies or sometimes writes about the Red Sox. But never music. He would sound stupid talking about music.