The CW, which this season scored its biggest homegrown success to date with “The Vampire Diaries,” opened midseason drama “Life Unexpected” to solid numbers Monday — a night that also saw CBS and ABC hit some season highs.

“Life,” in which a 15-year-old girl seeks out her biological parents, averaged a 1.2 rating/3 share in adults 18-49 and 2.7 million viewers overall, according to preliminary nationals from Nielsen, building a bit on its lead-in from “One Tree Hill” (1.1/3, 2.2 million). That’s the net’s largest audience in Monday’s 9 o’clock hour in a little over a year (“Gossip Girl”).

It also grew vs. “Hill” in adults 18-34 (1.7/4 vs. 1.5/4) and matched the firstrun season average of “Gossip Girl” this season. And in a good sign for a new 9 o’clock show, it built or held its audience in the 9:30 p.m. half-hour across the board.

While not big numbers, the premiere scores rep a promising preem for a young net that could use more building blocks. CW has also been mostly out of circulation for the last month-plus, making it more difficult to recruit auds to opening night.

“Life Unexpected,” from Mojo Films in association with Warner Bros. Television and CBS Prods., received generally favorable reviews and will air into spring as part of an all-original Monday sked that will see it either preceeding or following firstrun episodes of “One Tree Hill” or “Gossip Girl.”

Elsewhere, according to prelim Nielsen nationals, CBS’ “How I Met Your Mother” (4.0/10 in 18-49, 10.5 million viewers overall) and “Accidentally on Purpose” (3.5/9 in 18-49, 9.6 million viewers overall) seemed to benefit from the absence of usual timeslot leader “House” in scoring a narrow 18-49 victory in the night’s opening hour. That led into more strong numbers for “Two and a Half Men” (5.3/12 in 18-49, 16.2 million viewers overall) and “The Big Bang Theory” (5.2/12 in 18-49, 15.8 million viewers overall), which dominated the 9 o’clock hour in most key categories. At 10, “CSI: Miami” won as usual (3.6/10 in 18-49, 13.2 million viewers overall) but was on the low side.

ABC matched its best Monday demo delivery of the season with “The Bachelor” (3.8/9 in 18-49, 10.6 million viewers overall), where early-season controversy has resulted in a ratings bounce, and 10 p.m. sophomore drama “Castle” (2.8/8 in 18-49, 9.4 million viewers overall), which hit a season high in 18-49 and a series high in 18-34 (2.5/7).

At Fox, a two-hour episode of “24” on its regular night averaged a 3.4/8 in 18-49 and 11.0 million viewers overall, below last year and ranking third for its timeslot. It averaged a 3.6/8 in the demo during its normal 9 o’clock hour, where it will follow “House” beginning next week.

NBC started OK with “Chuck” (2.5/6 in 18-49, 6.7 million viewers overall), but “Heroes” hit another series low at 9 p.m. (1.8/4 in 18-49, 3.9 million viewers overall), leading into below-average deliveries for “The Jay Leno Show” (1.3/3 in 18-49, 4.6 million viewers overall).

In latenight, meanwhile, NBC’s “Tonight Show With Conan O’Brien” kicked off its final week of new shows Monday with another well-above-average demo delivery. “Tonight” averaged a 1.8 rating in adults 18-49 in Nielsen’s 25 local markets with People Meters, well above its fourth-quarter average (1.0) and double the 0.9 for CBS’ competing “Late Show With David Letterman.”


Due to the Monday holiday, the ratings charts and wrap-up that usually appear in Wednesday’s paper will instead run Thursday.