With NBC’s “The Voice” in clip-show mode, CBS dominated Tuesday’s first two hours behind “NCIS” and “NCIS: New Orleans” and prevailed in key demos overall on a night that saw Fox generate only moderate interest for its “American Idol” retrospective in advance of the music competition’s series finale on Thursday.

According to preliminary national estimates from Nielsen, “NCIS” ruled the night in both adults 18-49 (2.0 rating/7 share) and total viewers (15.4 million), matching its prior rating for an original of two weeks ago as the veteran refuses to fall below a 2 in the demo. “NCIS: New Orleans” (1.7/5 in 18-49, 12.2 million viewers overall) was down a tick from two weeks ago but led its hour in most categories, while “Limitless” (1.1/4 in 18-49, 6.2 million viewers overall) was down 0.2 from two weeks ago when it didn’t have to face an original “Chicago Fire” on NBC.

At Fox, the 90-minute “American Idol: The American Dream” averaged a 1.4/5 in 18-49 and 5.9 million viewers overall from 8 to 9:30 p.m., edging out in the demo a recap hour of competing music show “The Voice” on NBC (1.3/5 in 18-49, 6.7 million viewers overall). While these “Idol” numbers aren’t huge, they represent a big improvement over the 0.8 in the demo and less than 2 million total viewers the net has been averaging this spring with its comedies in the 8-9:30 p.m. time period. Despite a stronger lead-in, though, last night’s “Brooklyn Nine” (0.9/3 in 18-49, 2.8 million viewers overall) at a special 9:30 p.m. time was merely in line with recent results.

Despite a “Voice” recap, NBC dramas “Chicago Med” (1.5/5 in 18-49, 7.1 million viewers overall) and “Chicago Fire” (1.6/5 in 18-49, 7.7 million viewers overall) held up well. “Med” matched the show’s prior rating without a first-run “Voice” lead-in on Feb. 23 and pulled to within a tick of “NCIS: New Orleans” in 18-49 at 9:30 p.m., while “Fire” was No. 1 among the broadcasters at 10 p.m. for a 25th consecutive telecast against regular, first-run timeslot competition.

ABC’s “Fresh Off the Boat” (1.1/4 in 18-49, 4.2 million viewers overall) was down a tenth to match its season low, while “The Real O’Neals” (1.0/4 in 18-49, 3.7 million viewers overall) continues to hang there, posting the same rating for a fourth straight week and building slightly on “Boat” in adults 18-34 (0.64 vs. 0.59). The night when down from there with “Marvel’s Agents of SHIELD” (0.9/3 in 18-49, 2.9 million viewers overall), which matched its series low of two weeks ago, and “Beyond the Tank” (0.5/2 in 18-49, 2.0 million viewers overall), which at this point is doing worse than what repeats of just about any other ABC series might be doing in the 10 p.m. timeslot.

CW aired a repeat “The Flash” (0.4/2 in 18-49, 1.4 million viewers overall) and one of the season’s final original episodes of “iZombie” (0.4/1 in 18-49, 1.1 million viewers overall). The former returns in originals in two weeks, leading into new limited series “Containment.”