It was the night’s most-watched program overall, but ABC’s “Dancing With the Stars” was no match in demos for NBC’s “The Voice,” which dominated their head-to-head reality showdown Monday and teamed with a strong “The Blacklist” to lift NBC to victory among young adults.

According to preliminary national estimates from Nielsen, “Dancing With the Stars” averaged a 2.5 rating/7 share in adults 18-49 and 15 million viewers overall from 8 to 10 p.m., down in the demo by 19% from its fall premiere (3.1/9) and 22% lower than its year-ago spring premiere (3.2/8) — though neither of those faced “The Voice,” since last fall’s edition of “Dancing” began before the official start of the season, and its spring 2013 edition faced “The Biggest Loser” on NBC and not “The Voice.” Compared with its prior premiere against “The Voice” (fall 2012), “Dancing” was flat in the demo and up a bit in total viewers.

“Dancing” and “Castle” (1.8/5 in 18-49, 9.9 million viewers overall), which was up vs. its most recent original, combined for a second-place finish on the night in 18-49 and 25-54 while winning by about 700,000 total viewers over NBC.

At the Peacock, “The Voice” impressed with the premiere of its Battles round (4.0/12 in 18-49, 13.3 million viewers overall), up 8% from last week and ruling as Monday’s No. 1 program in demos by a wide margin. And at 10 p.m., “The Blacklist” (2.8/8 in 18-49, 11.1 million viewers overall) returned after a week off by dominating its hour in demos and winning in total viewers, up a bit from two weeks ago.

At CBS, “How I Met Your Mother” (2.9/9 in 18-49, 7.9 million viewers overall) stayed hot two weeks from its finale, rising 7% from last week and a solid second for its 8 o’clock half-hour in 18-49 and a first-place finish in adults 18-34 (2.8/10). The rest of the lineup sputtered, though, with “2 Broke Girls” (2.1/6 in 18-49, 7.1 million viewers overall), “Mike & Molly” (1.8/5 in 18-49, 7.6 million viewers overall), “Mom” (1.8/5 in 18-49, 7.1 million viewers overall) and “Intelligence” (1.1/3 in 18-49, 5.3 million viewers overall) all setting or matching lows.

Fox had a modest night with dramas “Bones” (1.4/4 in 18-49, 5.6 million viewers overall) and “The Following” (1.4/4 in 18-49, 4.0 million viewers overall), both of which hit lows; they were down 18% and 7% respectively from last week.

CW saw a pretty good start in its new time period for rookie drama “The Tomorrow People” (0.4/1 in 18-49, 1.2 million viewers overall), which built on its “Star-Crossed” lead-in (0.3/1 in 18-49, 1.1 million viewers overall). “Tomorrow” gave the network its top Monday since December 2012 (“Gossip Girl” finale) in key male demos and total viewers.

Preliminary 18-49 averages for the night: NBC, 3.6/10; ABC, 2.2/6; CBS, 1.8/5; Fox, 1.4/4; Univision, 1.0/3; CW and Telemundo, 0.4/1.

In total viewers: ABC, 13.3 million; NBC, 12.6 million; CBS, 6.7 million; Fox, 4.8 million; Univision, 2.5 million; CW and Telemundo, 1.1 million.