Friday Primetime Results:

* At 8 p.m., an encore telecast of "1600 Penn" averaged a 0.8/3 in 18-49 and 3.1 million viewers overall and at 8:30, a second "1600 Penn" rebroadcast averaged a 0.9/3 and 2.9 million viewers. "1600 Penn" grew from its first encore to its second in most key demographics, including a gain of 13 percent in 18-49 rating. The 8:30 "1600 Penn" rebroadcast earned three-week highs for NBC in the time period in 18-49 and total viewers.

* From 9-11 p.m. ET, Dateline NBC" averaged a 1.4/4 in 18-49 and 5.6 million viewers overall. From its first half-hour to its fourth, "Dateline" grew by 45 percent in adults 18-49 (to a 1.6 rating from a 1.1), by 50 percent in adults 25-54 (2.1 vs. 1.4) and 45 percent or 2.1 million persons in total viewers (6.6 million vs. 4.5 million). For its second hour from 10-11 p.m., "Dateline NBC" reported a 1.6/5 in 18-49 and 6.4 million, tying for #1 in the hour on ABC, CBS and NBC in adults 18-49 and ranking #1 outright among those networks in women 18-49.

In Late-Night Metered Markets Friday night:

* In Nielsen's 56 metered markets, household results were: "The Tonight Show with Jay Leno," 3.2/7; CBS's "Late Show with David Letterman," 2.7/6; and ABC's "Jimmy Kimmel Live," 2.4/6.

* In the 25 markets with Local People Meters, adult 18-49 Wednesday results were: "The Tonight Show with Jay Leno," 1.0/4; "Late Show," 0.6/3; and "Jimmy Kimmel Live," 0.8/4.

* From 12:35-1:05 a.m. ET Wednesday night, ABC's "Nightline" averaged a 1.5/4 in metered-market households and a 0.5/3 in 18-49 in the Local People Meters.

* Friday season averages heading into this week were: in metered-market households, "Tonight," 2.8 rating, 7 share; "Late Show," 2.5/6; "Nightline," 3.1/7; and "Jimmy Kimmel Live," 1.6/4. In the Local People Meters, 18-49 season averages for Friday were: "Tonight," 0.9/4; "Late Show," 0.6/3; "Nightline," 1.0/4; "Jimmy Kimmel Live," 0.6/3.

* From 12:35-1:35 a.m. ET, "Late Night with Jimmy Fallon" (1.7/5 in metered-market households) beat CBS's "Late Late Show with Craig Ferguson" (1.2/4). In the 25 markets with Local People Meters, "Late Night" (0.7/4 in 18-49) topped "Late Late Show" (0.3/2).

* At 1:35 a.m., "Last Call with Carson Daly" averaged a 1.0/4 in metered-market households with an encore and a 0.4/3 in adults 18-49 in the 25 markets with local people meters.

NOTE: All ratings are "live plus same day" from Nielsen Media Research unless otherwise indicated.