Fox’s dinosaur drama “Terra Nova” opened to decent numbers Monday, including a 3.0 rating among young adults and 9 million viewers overall. CBS’ “Two and a Half Men” brought back 20 million viewers for its second episode with Ashton Kutcher in the lead role, and that helped “Mike & Molly” achieve series highs.

CBS won the night in demos among the broadcasters, with “How I Met Your Mother” (4.4/12 in 18-49, 10.6 million viewers overall) holding up well from its premiere, and “2 Broke Girls” looking good in its regular 8:30 p.m. timeslot debut (4.5/11 in 18-49, 11.6 million viewers overall); combined the comedies were up about 25% from the opening hour of the second Monday a year ago for CBS, according to Nielsen. From there, “Two and a Half Men” dominated at 9 (7.2/17 in 18-49, 20.0 million viewers overall) — down about 30% week to week but still 50% better than the second week of “Men” last season for CBS (4.8). And following “Mike & Molly” (4.9/11 in 18-49, 14.0 million viewers overall), “Hawaii Five-0” led the drama demo battle at 10 p.m. (3.3/8 in 18-49, 11.1 million viewers overall), retaining nearly all of its week-ago season premiere.

As for Fox’s “Terra Nova,” its 3.0 rating/7 share in adults 18-49 ran third among the broadcasters on the night, with the rating holding steady at a 3.0 for its first three half-hour and then edging up to a 3.1 at 9:30. While nothing special, “Terra” did come within a tick or three of last week’s top drama premieres in the demo (ABC’s “Revenge” and “Pan Am” and CBS’ “Person of Interest”). A year ago in Week 2, “House” did a 3.8 and rookie dud “Lone Star” managed a mere 1.0, so Fox’s 3.0 average for the night is a 20% improvement year-to-year. “House” returns next week, moving to its new regular 9 p.m. timeslot.

ABC’s “Dancing With the Stars” (3.3/8 in 18-49, 16.0 million viewers overall) dropped about 15% from its below-par premiere of last week and was down a big 30% from the same night a year ago, but it was still big enough among older viewers to lift the Alphabet to victory for the night in total viewers. Closing things out, 10 p.m. drama “Castle” (2.9/7 in 18-49, 11.1 million viewers overall) still managed to roughly match its delivery of a year ago, placing second to “Hawaii Five-0” in demos while edging out the CBS drama in total viewers.

NBC’s “The Playboy Club” (1.3/4 in 18-49, 3.9 million viewers overall) dropped a few more ticks from its soft bow, and the net’s “The Sing-Off” also dipped (1.7/4 in 18-49, 4.4 million viewers overall), with all three hours below last year’s Week 2 average. For the night, the Peacock figures to finish in sixth or seventh place in 18-49 — lagging not only its major-network rivals but also Spanish-language broadcaster Univision and at least one cable network (ESPN, with “Monday Night Football”).

CW’s new drama “Hart of Dixie” averaged a 0.8/2 in 18-49 and 1.8 million viewers overall), matching or building on its “Gossip Girl” lead-in (0.8/2 in 18-49, 1.4 million viewers overall) in all broad categories — though it dropped off in adults 18-34 (0.8 vs. a 1.1 for “Gossip”).

Preliminary 18-49 averages for the night: CBS, 4.6/11; ABC, 3.1/8; Fox, 3.0/7; Univision, 1.7/4; NBC, 1.5/4; CW, 0.8/2.

In total viewers: ABC, 14.6 million; CBS, 13.0 million; Fox, 9.0 million; NBC, 4.2 million; Univision, 4.1 million; CW, 1.6 million.