Fast National ratings for Monday, January 18, 2010.

In its Monday premiere, FOX's "24" delivered OK numbers, while The CW got a strong launch for the series debut of "Life Unexpected." Neither of those things made a difference as CBS dominated the second half of the evening for Monday wins in most key measures.

Among adults 18-49, CBS averaged a 4.2 rating, beating the 3.5 rating for ABC and FOX's 3.4 rating in the key demographic. NBC was a distant fourth with a 1.9 rating, leaving The CW's 1.1 rating in fifth.

Overall, CBS averaged an estimated 12.94 million viewers to go with a 7.7 rating/12 share. ABC's 6.5/10 nipped the 6.4/9 for FOX, though FOX averaged more total viewers. NBC was well back in fourth with a 3.1/5. The CW's 1.6/2 was good for fifth.

ABC started the night in first with a 6.4/10 for "The Bachelor." CBS' "How I Met Your Mother" and "Accidentally on Purpose" were second overal with a 6.0/9 and first in the key demo with a 3.7 rating. The first hour of FOX's "24" was third with a 6.1/9. NBC's "Chuck" was fourth with a 3.9/6 and a 2.5 rating in the demo. The CW's "One Tree Hill" return finished fifth.

CBS moved into first at 9 p.m. with the 9.1/13 for "Two and a Half Men" and "The Big Bang Theory," which also combined to win the hour in the key demographic with a 5.3 rating. [Odd note on the CBS numbers: For the first time in weeks, "Two and a Half Men" beat "Big Bang Theory" among adults 18-49.] ABC's "The Bachelor" was second overall and in the demo. FOX's "24" improved to a 6.6/10 in its second hour. On NBC, "Heroes" had a 2.4/4 and a 1.8 rating in the demo. The CW's premiere of the critically adored "Life Unexpected" did a 1.7/3, averaging 2.74 million viewers and a 1.2 demo rating, all pretty good by the netlet's standards.

"CSI: Miami" had an 8.2/14 and a 3.6 demo rating to close the night in first for CBS. ABC's "Castle" did a 6.0/10 for second. NBC's "The Jay Leno Show" trailed.

All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.

A long-time member of the TCA Board and a longer-time blogger of "American Idol," Dan Fienberg writes about TV, except for when he writes about movies or sometimes writes about the Red Sox. But never music. He would sound stupid talking about music.