CBS'S REGULAR THURSDAY LINEUP RETURNS FROM ITS SUMMER SABBATICAL TO DOMINATE THE COMPETITION

The Fourth Season Premiere of "Without a Trace" Beats "ER" By Its Largest Margin Ever in Viewers and Adults 25-54

"Survivor: Guatemala" Up Over Last Week Despite Increased Competition

"CSI" Rules The Night With More Than 27 Million Viewers

CBS's regular Thursday lineup -- SURVIVOR, CSI and WITHOUT A TRACE -- returned intact for the first time since last May and once again dominated the competition in viewers and key demographics, according to preliminary Nielsen affiliate ratings for Sept. 29.

At 10:00 PM, the fourth season premiere of WITHOUT A TRACE won its time period in households (13.8/22), viewers (21.13m), adults 25-54 (8.0/19) and a very close second in adults 18-49 (6.4/17, -0.2 behind NBC's "ER").

WITHOUT A TRACE beat "ER" by +47% in households (vs. 9.4/15), +10% in adults 25-54 (7.3/18) and +6.94m viewers (from 14.19m).

This is the largest margin of victory ever for a first run episode of WITHOUT A TRACE against a first run "ER" in viewers. In adults 25-54, this is also the largest margin of victory ever and only the second time WITHOUT A TRACE has topped "ER" in this demographic. Last night was also the smallest difference, -0.2, between first run episodes of WITHOUT A TRACE and "ER" in adults 18-49.

From 9:00-10:00 PM, CSI finished first in households (17.0/26), viewers (27.20m), adults 25-54 (11.1/25), adults 18-49 (9.1/22) and adults 18-34 (7.1/20) and was the night's most watched and highest rated program in households, adults 18-34, adults 18-49 and adults 25-54.

SURVIVOR: GUATEMALA won its time period with a 10.5/17 with 17.13m viewers, 7.1/18 in adults 25-54 and 5.6/15 in adults 18-49.

Despite increased competition from the premieres of "Alias," "Smallville" and a live season premiere broadcast of "Will & Grace," SURVIVOR built on last week's audience by +150,000 viewers (from 16.98m).

SURVIVOR: GUATEMALA beat second place NBC ("Joey" and the season premiere of "Will & Grace") by +81% in households (vs. 5.8/09), +56% in adults 18-49 (vs. 3.6/10) and +73% in adults 25-54 (4.1/10) and nearly doubled NBC in viewers (+8.56m viewers, from 8.57m).

For the night, CBS was first in households (13.8/22), viewers (21.82m), adults 25-54 (8.7/21), adults 18-49 (7.0/18) and adults 18-34 (5.2/15).

Final Thursday ratings will be available this afternoon.

[EDITOR'S NOTE: What follows is the afternoon update with the final national Nielsen ratings.]

CBS'S REGULAR THURSDAY LINEUP RETURNS FROM ITS SUMMER SABBATICAL TO DOMINATE THE COMPETITION

The Fourth Season Premiere of "Without a Trace" Beats "ER" By Its Largest Margin Ever in Viewers and Adults 25-54

"Survivor: Guatemala" Up Over Last Week Despite Increased Competition

"CSI" Rules The Night With 28 Million Viewers

CBS's regular Thursday lineup -- SURVIVOR, CSI and WITHOUT A TRACE -- returned intact for the first time since last May and once again dominated the competition in viewers and key demographics, according to final national Nielsen ratings for Sept. 29.

The fourth season premiere of WITHOUT A TRACE won its 10:00 PM time period in households (13.8/22), viewers (20.98m), adults 25-54 (7.9/19) and a very close second in adults 18-49 (6.4/17, -0.2 behind NBC's "ER").

WITHOUT A TRACE beat "ER" by +45% in both households (vs. 9.5/15) and viewers (vs. 14.44m, +6.54m) and +7% in adults 25-54 (vs. 7.4/18).

This is the largest margin of victory ever for a first run episode of WITHOUT A TRACE against a first run "ER" in viewers. In adults 25-54, this is also the largest margin of victory ever and only the second time WITHOUT A TRACE has topped "ER" in this demographic. Last night was also the smallest difference, -0.2, between first run episodes of WITHOUT A TRACE and "ER" in adults 18-49.

At 9:00 PM, CSI finished first in households (17.4/26), viewers (28.00m), adults 25-54 (11.5/26), adults 18-49 (9.4/23) and adults 18-34 (7.3/20) and was the night's most watched and highest rated program in households, adults 18-34, adults 18-49 and adults 25-54. CSI beat NBC, ABC and FOX combined in households (vs. 14.8/22, +18%), viewers (vs. 22.10, +27%) and adults 25-54 (vs. 10.4/23, +11%) and in a virtual tie in adults 18-49 (vs. 9.7/24 for three networks).

SURVIVOR: GUATEMALA won its time period with a 10.6/17 with 17.29m viewers, 7.2/18 in adults 25-54 and 5.7/16 in adults 18-49.

Despite increased competition from the premieres of "Alias," "Smallville" and a live season premiere broadcast of "Will & Grace," SURVIVOR built on last week's audience by +310,000 viewers (from 16.98m).

SURVIVOR: GUATEMALA beat second place NBC ("Joey" and the season premiere of "Will & Grace") by +80% in households (vs. 5.9/09), +54% in adults 18-49 (vs. 3.7/10) and +71% in adults 25-54 (vs. 4.2/11) and nearly doubled NBC in viewers (+8.62m viewers, vs. 8.67m).

For the night, CBS was first in households (13.9/22), viewers (22.13m), adults 25-54 (8.9/21), adults 18-49 (7.2/19) and adults 18-34 (5.3/16).