Fast National ratings for Thursday, April 24, 2014.

On a weak Thursday across-the-board, "The Big Bang Theory" had its lowest-rated episode of the season, but still led CBS to comfortable primetime domination in all measures.

CBS' new comedy "Bad Teacher" got off to a decent, but unspectacular, start as it outperformed most recent airings of the now-departed "Crazy Ones" and also topped the Monday numbers for fellow freshman comedy "Friends With Better Lives." "Bad Teacher" retained most of its key demo lead-in from "Two and a Half Men."

That's qualified praise for "Bad Teacher" and, similarly, ABC can probably muster a little enthusiasm for "Black Box," which ranks as the network's second best drama premiere of the spring, not that that's saying a whole lot. ABC went so far as to call this the network's most-watched 10 p.m. drama debut since "Nashville" in 2012.

Relative to last week's Fast Nationals, "American Idol" and "Grey's Anatomy" were both down, "Parks and Recreation" and "Reign" were up a little and "Hell's Kitchen" and "Surviving Jack" were flat.

On to the numbers...

Among adults 18-49, CBS averaged a 2.4 rating for Thursday night, tops in the key demographic. FOX was a distant second with a 1.5 key demo rating, followed closely by ABC's 1.4 key demo rating. NBC's 1.0 key demo rating and the 0.6 key demo rating for The CW followed.

Overall, CBS also won commandingly, averaging an estimated 9.945 million viewers and a 6.2 rating/10 share for Thursday primetime. ABC was second with 5.66 million viewers and a 3.9/6, topping the 5.29 million viewers and 3.2/5 for FOX. NBC's 1.7/3 and 2.54 million viewers beat the 1.1/2 and 1.59 million for The CW.

[Univision averaged 2.88 million and a 1.1 rating among adults 18-49 for the night.]

8 p.m. - CBS started primetime in first with "The Big Bang Theory" (15.96 million and a 4.3 key demo) and "The Millers" (10.15 million and a 2.5 key demo). There was a rather large drop to FOX's "Hell's Kitchen" in second with 4.82 million viewers and a 1.7 rating among adults 18-49. The Jimmy Kimmel special "Behind the Scandalabra" drew an unimpressive 2.75 million viewers for third and a 0.6 key demo rating for fifth. NBC's "Parks and Recreation" finale was fourth with 2.71 million viewers and third with a 1.0 key demo rating. The CW's "The Vampire Diaries" averaged 1.79 million viewers and a 0.7 key demo rating.

9 p.m. - CBS stayed in first overall and tied for first in the key demo with  "Two and a Half Men" (9.46 million and a 2.5 key demo) and the series premiere of "Bad Teacher" (7.87 million and a 2.1 key demo rating). ABC's "Grey's Anatomy" averaged 7.64 million viewers and a  2.3 key demo rating. FOX was far back in third with "American Idol" (7.6 million and a 1.8 key demo) and "Surviving Jack" (3.93 million and a 1.0 key demo). The first hour of NBC's "SNL Shorts" special averaged 2.46 million viewers and a 1.0 key demo rating, ahead of the 1.38 million viewers and 0.5 key demo rating for The CW's "Reign."

10 p.m. - "Elementary" won the 10 p.m. hour with 8.115 million viewers and scored a narrow win with a 1.6 rating among adults 18-49, failing to get a bump from the absence of "Scandal." ABC's "Black Box" premiere averaged 6.59 million viewers and a 1.5 key demo rating, beating "Elementary" in the 18-34 demo and in all female demos. ["Black Box" dipped a little at the half-hour, but so did "Elementary."] NBC's "SNL Shorts" was third with 2.45 million viewers and a 1.0 key demo rating.

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