CBS was the No. 1 broadcaster in key demos in all six half-hours of primetime Monday, as the net’s comedy anchors ”How I Met Your Mother” and ”Two and a Half Men” continue to outperform last year’s ratings levels. ABC’s ”Dancing With the Stars” was on the rise, though still down year to year, but it was another weak showing for NBC’s new Brian Williams newsmag.

According to preliminary Nielsen estimates, the CBS comedies accounted for Monday’s top four entertainment-series scores among young adults, led as usual by ”Two and a Half Men” (5.1 rating/12 share in adults 18-49, 14.5 million viewers overall) — the night’s No. 1 broadcast in 18-49, rising 19% vs. the same night a year ago. All of the network’s programs were up vs. the comparable Monday timeslot perf of last year, with 8 p.m. anchor ”How I Met Your Mother” (4.4/12 in 18-49, 10.4 million viewers overall) up 25% over its year-ago showing, and 8:30 p.m. newbie ”2 Broke Girls” (4.5/11 in 18-49, 11.3 million viewers overall) up a big 50% over last year’s ”Rules of Engagement.” Closing out the night, ”Mike and Molly” (4.2/10 in 18-49, 12.0 million viewers overall) was up 20% over its year-ago score, and 10 p.m. drama ”Hawaii Five-0” (3.0/8 in 18-49, 10.0 million viewers overall) was up a tick to easily top its broadcast competition in demos for the hour.

At ABC, ”Dancing With the Stars” (3.3/8 in 18-49, 18.0 million viewers overall) rallied to its best delivery since its season premiere, but that still left it about 15% below last year’s performance on the comparable night; it remained the evening’s most-watched entertainment series overall. And at 10, ”Castle” (2.5/6 in 18-49, 11.3 million viewers overall) was in line with its performance of last year, also leading its timeslot broadcast competition in total viewers.

Fox’s ”Terra Nova” (2.6/6 in 18-49, 7.7 million viewers overall) bounced back from last week to place third among the broadcasters in the 8 o’clock hour. The net maintained that standing at 9 p.m. with ”House” (2.7/6 in 18-49, 7.5 million viewers overall), which was considerably stronger a year ago in the leadoff position (3.7/10 in 18-49).

NBC again struggled, as ”The Sing Off” settled for a 1.4/3 in 18-49 and 4.2 million viewers overall, and newsmag ”Rock Center with Brian Williams” (1.0/3 in 18-49, 3.5 million viewers overall) was on par with its low-rated debut of the previous week.

ESPN will win the night in key demos with its ”Monday Night Football” matchup between the Chicago Bears and Philadelphia Eagles, which averaged a strong 11.7 household rating in Nielsen’s metered-market overnights. In addition to the cable net, the game also aired in the local markets on independent stations, thus not affecting the preliminary overnights of the Big Four.

Preliminary 18-49 averages for the night: CBS, 4.0/10; ABC, 3.1/8; Fox, 2.7/6; NBC and Univision, 1.3/3; CW, 0.6/1.

In total viewers: ABC, 15.8 million; CBS, 11.4 million; Fox, 7.6 million; NBC, 4.0 million; Univision, 3.2 million; CW, 1.3 million.