CBS ran away with the ratings crown on the first Tuesday of the New Year with predominantly regular programming, as “NCIS” and “NCIS: Los Angeles” obliterated the competition in key demos. Also of note, NBC’s “Off Their Rockers” opened with OK numbers in the opening hour, but the net’s rookie comedy block struggled behind it.

According to preliminary national estimates from Nielsen, CBS vet “NCIS” was easily Tuesday’s top program in 18-49 (3.5/10), 25-54 (5.2/13) and total viewers (20.9 million), starting the year off with its largest overall audience of the season. And “NCIS: Los Angeles” (3.0/8 in 18-49, 17.8 million viewers overall) continues to mow down the comedies opposite it on ABC, NBC and Fox, and also hit a season high in total viewers. The net then lost its young-adult leadership at 10 p.m. with “Vegas” (1.6/4 in 18-49, 10.8 million viewers overall), though it narrowly won the hour among adults 25-54 (2.5/6) and comfortably led as usual in total viewers.

For the night, CBS beat runner-up NBC by 59% in 18-49, by 82% in 25-54 and more than tripled it in total viewers.

The Peacock kicked off the night with back-to-back original episodes of “Betty White’s Off Their Rockers” (1.5/4 in 18-49, 5.7 million viewers overall at 8 and 1.8/5 in 18-49, 6.1 million viewers overall at 8:30); while nowhere close to what it was doing here earlier this season with “The Voice,” it’s a decent stop-gap and left the net second among the Big Four in most categories in the 8 o’clock hour.

But the softer lead-in made for a more competitive comedy race at 9 as NBC’s “Go On” (1.5/4 in 18-49, 4.3 million viewers overall) and “The New Normal” (1.3/3 in 18-49, 3.3 million viewers overall) hit lows, down 38% and 24% respectively from their most recent originals on Dec. 4 (behind “The Voice”).

Fox’s “New Girl” (2.0/5 in 18-49, 3.8 million viewers overall), holding steady with its most recent original five weeks ago, won the 9 o’clock comedy battle in 18-49 by a 33% margin over “Go On” and by 43% over “Happy Endings”; it also was the night’s top Big Four program in adults 18-34 (2.2/6). And the net’s rookie laffer “The Mindy Project” prevailed at 9:30 (1.5/4 in 18-49, 2.8 million viewers overall), also matching its last original and retaining a pretty good 75% of its lead-in.

Opening the night, “Raising Hope” (1.7/5 in 18-49, 3.8 million viewers overall) matched its last original and “Ben & Kate” (1.2/3 in 18-49, 2.5 million viewers overall) was up a tick. “Hope” was the night’s top Big Four series in teens (1.2/5).

ABC kept the lights on in the 8 o’clock hour with special repeats of Wednesday comedies “Modern Family” (1.7/5 in 18-49, 5.8 million viewers overall) and “The Middle” (1.5/4 in 18-49, 4.8 million viewers overall), and that seemed to help “Happy Endings” (1.4/4 in 18-49, 3.8 million viewers overall), which was up a tick from its most recent Tuesday original and nearly caught NBC’s “Go On” in 18-49. The net dropped off from there with “Don’t Trust the B in Apt. 23” (1.1/3 in 18-49, 3.2 million viewers overall) and “Private Practice” (1.1/3 in 18-49, 3.9 million viewers overall).

CW aired a repeat “Hart of Dixie” (0.3/1 in 18-49, 0.8 million viewers overall) and an original “Emily Owens, M.D.” (0.3/1 in 18-49, 1.1 million viewers overall).

Preliminary 18-49 averages for the night; CBS, 2.7/7; NBC, 1.7/5; Fox and Univision, 1.6/4; ABC, 1.3/4; CW, 0.3/1.

In total viewers: CBS, 16.5 million; NBC, 5.0 million; ABC, 4.2 million; Univision, 3.9 million; CW, 0.9 million.