CBS won Tuesday’s ratings race behind “NCIS” and “NCIS: Los Angeles,” though the former was on the low end with the second of two episodes setting up a potential spinoff. NBC was a solid second on the night, with “The Voice” falling off but rookie comedies “About a Boy” and “Growing Up Fisher” looking more and more like keepers.

According to preliminary national estimates from Nielsen, “NCIS” averaged a season-low 2.3 rating/8 share in adults 18-49 and 16.8 million viewers overall kicking off the night, down 8% from last week when it introduced Scott Bakula and other characters that would form “NCIS: New Orleans,” if picked up in the fall. It was followed by “NCIS: Los Angeles” (2.4/7 in 18-49, 15.2 million viewers overall), which built slightly on its lead-in in rating to match last week’s score and stand as the night’s No. 1 scripted program in 18-49. At 10 p.m., “Person of Interest” (1.9/6 in 18-49, 11.5 million viewers overall) beat the combined scores of the repeat dramas on NBC and ABC.

At NBC, “The Voice” (3.0/10 in 18-49, 11.8 million viewers overall) declined 12% from last week to a low for this edition, but still stood as Tuesday’s No. 1 program in 18-49 and 25-54 (4.1/12). The standouts of the night for NBC, though, were first-year laffers “About a Boy” (2.1/6 in 18-49, 7.5 million viewers overall) and “Growing Up Fisher” (1.7/5 in 18-49, 6.1 million viewers overall). Despite the softer lead-in, they were on par with last week, and this makes it four straight weeks that “Boy” has been at either a 2.0 or 2.1 while “Fisher” (pictured) has been at 1.7 or 1.8.

A repeat of “Chicago Fire” closed the night for NBC (1.0/3 in 18-49, 4.3 million viewers overall).

At ABC, “Marvel’s Agents of SHIELD” (1.8/6 in 18-49, 5.4 million viewers overall) was back after a two-week break, declining 14% (0.3) from its prior original (which went up against an “NCIS” repeat). Though it pulled to within half a ratings point of “NCIS,” this figures to be the second lowest demo score to date for “SHIELD,” coming in the same week that Marvel releases “Captain America.”

Also for ABC, “The Goldbergs” (1.5/4 in 18-49, 4.5 million viewers overall) was down 12% from its prior original, and “Trophy Wife” held steady (1.0/3 in 18-49, 2.9 million viewers overall). A special repeat of Sunday drama “Resurrection” aired at 10 p.m. for ABC, matching the score for last week’s original episode of “Mind Games.”

Fox ran fourth among the Big Four in 18-49 with “Glee” (0.9/3 in 18-49, 2.6 million viewers overall) and the return of “The Mindy Project” (1.0/3 in 18-49, 1.9 million viewers overall for an hourlong episode) — two low-rated shows that have been renewed for next season.

CW aired repeats of “The Originals” (0.3/1 in 18-49, 0.7 million viewers overall) and “The 100” (0.3/1 in 18-49, 0.9 million viewers overall).

Preliminary 18-49 averages for the night: CBS, 2.2/7; NBC, 2.0/6; ABC, 1.3/4; Univision, 1.1/3; Fox, 0.9/3; Telemundo, 0.5/1; CW, 0.3/1.

In total viewers: CBS, 14.5 million; NBC, 7.6 million; ABC, 3.9 million; Univision, 2.7 million; Fox, 2.3 million; Telemundo, 1.5 million; CW, 0.8 million.