Fast National ratings for Tuesday, October 1, 2013.
 
ABC's glow from "Marvel's Agents of S.H.I.E.L.D." lasted only a week as the "Avengers" spinoff took a steep drop in its second airing. While the numbers for "S.H.I.E.L.D." were still OK out of context, the reduced lead-in also dropped "The Goldbergs" and sent "Trophy Wife" and particularly "Lucky 7" heading into the Danger Zone.
 
While ABC had the dramatic results, the network wasn't a factor in the night's big races. Also a non-factor was FOX, which saw its two-hour comedy block continue to slide, with "Dads" and "Brooklyn Nine-Nine" now low-rated twins.
 
"NCIS" and "Person of Interest" held onto most of their premiere audiences and led CBS overall, while "The Voice" and "Chicago Fire" helped NBC maintain its domination among young viewers. 
 
On to the numbers...
 
Among adults 18-49, NBC averaged a 3.8 rating for Tuesday night, tops in the key demographic. CBS was second with a 2.7 rating, followed by ABC's 1.9 key demo rating and the 1.5 key demo rating for FOX. The CW averaged a 0.4 key demo rating for Tuesday.
 
Overall, though, CBS dominated with an estimated 15.43 million viewers and a 9.6 rating/15 share for Tuesday primetime, topping the 12.47 million viewers and 7.6/12 for NBC. ABC was third with 5.49 million viewers and a 3.4/6, beating the 2.1/3 and 3.42 million viewers for FOX. The CW averaged a 0.7/1 and 1.09 million viewers.
 
8 p.m. - "NCIS" ruled the 8 p.m. hour with 19.33 million viewers for CBS, coming in second with a 3.4 rating among adults 18-49. NBC's "The Voice" was second overall with 12.42 million viewers and led the hour with a 3.8 key demo rating. After leading the hour among young viewers last week with a 4.6 rating in Fast Nationals, ABC's "Marvel's Agents of S.H.I.E.L.D." slipped to third with a 3.1 key demo rating and also finished third with 8.44 million viewers (down from 11.9 million). FOX was fourth with the nearly identical ratings for "Dads" (3.418 million viewers and a 1.3 key demo) and "Brooklyn Nine-Nine" (3.422 million and a 1.4 key demo rating). The CW's second night of IHeartRadio concert coverage averaged 1.1 million viewers and a 0.4 key demo rating.
 
9 p.m. - NBC took over first for the 9 p.m. hour with 15.99 million viewers and a 5.0 rating among adults 18-49 for "The Voice." CBS' "NCIS: Los Angeles" posted somewhat large declines from last week, but finished second with 14.79 million viewers and a 2.7 key demo rating. ABC was third with "The Goldbergs" (6.16 million and a 2.2 key demo) and a big drop to "Trophy Wife" (4.28 million and a 1.4 key demo). FOX was fourth with "New Girl" (3.89 million and a 1.9 key demo) and "The Mindy Project" (2.96 million and a 1.5 key demo), with "Mindy" offering a rare ray of hope by staying flat week-to-week and beating "Trophy Wife" in the demo. The CW's concert footage averaged 1.08 million viewers and a 0.4 key demo rating.
 
10 p.m. - "Person of Interest" won the 10 p.m. hour for CBS with 12.16 million viewers, but finished second with a 2.0 rating among adults 18-49, down from a 2.3 key demo last week. NBC's "Chicago Fire" averaged 9 million viewers and 2.8 key demo rating, encouragingly flat from last week. ABC's "Lucky 7" drew 2.8 million viewers and a 0.8 key demo rating, down by 50 percent from last week's already dismal premiere.
 
All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.