• by Wayne Friedman , March 10, 2010

CBS has been getting the best of NBC's late-night and 10 p.m. moves recently. 

Now a week into Jay Leno's return to "The Tonight Show," "Late Show with David Letterman" has -- for the last two days anyway -- significantly closed the gap.

On Monday, "Late Show" posted a 1.3 rating among adults 18-49, with "Leno" at a 1.1 rating, which was the average rating Conan O'Brien was earning when he departed.

On Tuesday, "Letterman" lost ground, with "Leno" showing no improvement.

"Late Show" drifted back to a Nielsen 0.9 rating among 18-49 viewers. The "Tonight Show" earned the same results on Tuesday -- a 1.1 rating -- as Monday. "Tonight" was also still slightly ahead of "Late Show" in overall viewers - 4.2 million to 4.0 million. ABC's "Nightline" was at a 0.9 rating and 3.3 million viewers.

CBS also managed to grab back its Tuesday 10 p.m. time period lead with "The Good Wife" earning a 2.9/8, with NBC's "Parenthood" slipping 16%, to a 2.6 rating/8 share. ABC's "the forgotten" earned a 1.3/4 in the time period.

Fox's "American Idol" dominated the earlier evening prime-time schedules, at an 8.4/23 among 18-49 viewers -- down a bit from the Tuesday, the week before. Better news was that a repeat of "Glee" at 9 p.m. took in a healthy 3.0/9.

The second-biggest player of the night, ABC's "Lost," was steady -- up a fraction to a 4.3/11.

CBS' "NCIS" franchise had some good and bad news. The original show, "NCIS," dropped 5% to 3.9/11 at 8 p.m., while "NCIS: LA" climbed 15% to a 3.5/9 at 9 p.m.

NBC's "The Biggest Loser" was on the losing end this week, down a couple of tenths of a rating point to a 3.0/8 for a two-hour show.

CW didn't do much for its women 18-34 viewers: "90210" pulled in a ho-hum 1.3 rating with "Melrose Place" about half of those results at a 0.7 number.

For prime time, Fox was first among 18-49 viewers with a 5.6/15, followed by CBS with a 3.4/9; NBC at 2.9/8; ABC at 2.4/7; Univision at 1.3/4; and CW with a 0.7/2.