Fast National ratings for Tuesday, November 20, 2012.

The "NCIS" shows powered CBS to a narrow ratings victory on Tuesday night among young adult, and a commanding one among total viewers.

For the night, CBS averaged a 2.5 rating among adults 18-49, and 13.91 million viewers overall. Thanks largely to "The Voice," NBC was second (2.3, 6.38 million), followed by FOX (1.5, 3.25 million), ABC (1.4, 7.01 million) and the CW (0.5, 1.24 million).

8 p.m. -- "The Voice" won the hour in the demo for NBC with a 3.3 rating and 9.33 million viewers. On CBS, "NCIS" averaged a 3.0 rating and 16.47 million viewers overall. ABC's "Dancing with the Stars" (1.9, 12.87 million) was third (and an overwhelming second in total viewers), followed by "Raising Hope" and "Ben and Kate" on FOX (1.3, 3.11 million) and "Hart of Dixie" on the CW (0.5, 1.21 million).

9 p.m. -- CBS' "NCIS: LA" (2.8, 15.06 million) continued its dominance over the comedy blocs on NBC ("Go On" and "The New Normal" combined for 1.9, 5.28 million), FOX ("New Girl" and "The Mindy Project" combined for a 1.7 and 3.39 million) and ABC ("Happy Endings" and "Don't Trust the B---- in Apt. 23" averaging a 1.1 and 4.03 million). The CW's "Emily Owens, M.D." (0.4, 1.27 million) was way off in the distance.

10 p.m. -- CBS' "Vegas" (1.8, 10.2 million) narrowly won the hour in the demo and easily eclipsed NBC's "Parenthood" (1.6, 4.52 million) and ABC's "Private Practice" (1.2, 4.14 million) in total viewers.

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