As ratings drift downward for most of TV’s top shows, the network benefiting most is the one with the most bench strength across the week: CBS.

Last week, the Eye — bolstered by week-two gains for rookie “The Mentalist” — bested its primetime competition in key demos even though ABC, NBC and Fox claimed the week’s top three programs. CBS was the most balanced of the nets, getting nice contributions from comedy, drama, reality, news and sports.

Frame was thrown off by Thursday’s VP debate, which sidelined the night’s heavyweight shows such as ABC’s “Grey’s Anatomy,” CBS’ “CSI” and NBC’s “The Office.” It also featured the start of the baseball playoffs, which scored nicely for exclusive carrier TBS and likely took away some auds from entertainment series in big markets like Los Angeles, Chicago and Boston.

Overall, according to Nielsen estimates, CBS ruled the Sept. 29-Oct. 5 frame among adults 18-49 with a 3.2 rating/9 share, comfortably ahead of ABC and NBC, which tied for second at 2.8/8. Fox ran fourth (2.5/7), followed by TBS (1.6/4), Univision (1.5/4) and CW and ESPN (both 1.1/3).

As is typical when the Eye wins in 18-49, the net was especially dominant in its core 25-54 demo (4.1/10, beating No. 2 ABC by 24%) and cruised to victory in total viewers (11.1 million to 9.2 million for ABC).

CBS was the top network in adults 18-49 on four nights (Monday, Wednesday, Thursday and Friday) while placing a competitive second on Tuesday, where it drew its largest overall aud on the night since 2005.

Leading the way with top-10 demo finishes were Monday comedy “Two and a Half Men” (4.7/11 in 18-49, 13.58 million viewers overall), Thursday reality vet “Survivor” (4.5/12, 13.08m) and Monday drama “CSI: Miami” (4.4/11, 14.34m).

Also shining were its crime drama tandems on Tuesday with “NCIS” (3.5/10, 17.47m) and “The Mentalist” (3.6/9, 15.48m) and on Wednesday with “Criminal Minds” (3.9/10, 14.78m) and “CSI: NY” (4.1/11, 14.88m). “Mentalist” improved slightly upon its solid week-earlier premiere, while “NCIS” was the week’s most-watched scripted show.

CBS also benefited from a 30-minute NFL overrun Sunday (8.6/26 in 18-49, 24.87m), which helped “60 Minutes” (4.0/11, 16.65m) dominate its slot. And “Elite XC Saturday Night Fights” (2.0/6, 4.56m) was the Saturday’s top show among young males — even up against college football on ESPN and baseball on TBS.

Meanwhile, CBS hasn’t gotten much out of new comedies “Worst Week” on Monday (2.9/7, 8.96m) or “Gary Unmarried” on Wednesday (2.2/6, 6.91m). And the preem of romantic hour “The Ex List” (2.0/6, 6.79m) won its Friday hour but was unspectacular behind the dominant “Ghost Whisperer” (2.5/9, 9.45m).

ABC was paced by “Desperate Housewives” (5.8/13 in 18-49, 15.69m) and “Dancing With the Stars” (4.4/11, 18.88m), though both were down from their preems. “Housewives” was the week’s No. 1 show in 18-49, while the hoofing skein drew the week’s largest overall aud.

Wednesday saw surprisingly tame results for the net’s returning sophomore skeins, each of which hadn’t aired on the night in more than nine months (Daily Variety, Oct. 3). The score for “Private Practice” was still credible enough (second-place 3.3/8 in 18-49, 8.16m), but lead-in “Pushing Daisies” wilted in its comeback (2.0/6, 6.33m).

NBC was led by “Sunday Night Football” (5.5/14 in 18-49, 14.21m for Pittsburgh-Jacksonville), which was No. 2 for the week despite hitting a season low. Also in the top 20 for the net were “Heroes” (4.5/11, 9.50m), “Law & Order: SVU” (3.8/11, 10.39m) and the news division’s post-debate coverage on Thursday.

Peacock ran third with its pair of long-delayed soph skeins, “Chuck” on Monday (2.7/7, 6.84m) and “Life” on Friday (1.7/5, 5.54m), though the latter was competitive in its timeslot and built on its lead-in. And new Wednesday drama “Knight Rider” held up well in its second try (2.4/7 in 18-49, 7.77m), beating ABC and CBS in its hour.

Fox was hot and cold to start the week with its dramas, as Monday’s “Terminator: The Sarah Connor Chronicles” (2.0/5 in 18-49, 5.37m) and “Prison Break” (2.1/5, 5.28m) looked shaky but Tuesday’s “House” (5.4/15, 12.98m) and “Fringe” (4.2/11, 9.91m) topped their hours in 18-49. “House” was the sesh’s No. 3 show in the demo, rising week to week.

“Bones” won its hour on Wednesday (3.2/9, 10.03m), and “Family Guy” remains potent on Sunday (4.3/10, 8.38m).

CW had a good start to the week, as “Gossip Girl” (1.8/5 in 18-49, 3.40m), “One Tree Hill” (1.9/4, 3.42m) and “90210” (1.7/5, 3.25m) all grew vs. the previous week. Not so hot were the net’s new Sunday hours (Daily Variety, Oct. 6). Friday’s launch of returning comedies “Everybody Hates Chris” (0.8/3, 2.11m) and “The Game” (0.8/3, 1.95m) did OK on a tough night.

MyNetwork had its best week to date, averaging a 0.6/2 in 18-49 and 1.73 million viewers overall, led by Friday’s bow of “WWE Smackdown” (1.0/3 in 18-49, 3.16m). Also clicking was a WWE special, Thursday’s “Magic’s Biggest Secrets Finally Revealed” (0.9/2, 2.26m).

TBS was the easy leader in cable thanks to coverage of baseball’s opening round of playoffs. Top draws were Sunday’s Game 3 of the American League Divisional Series between the Boston Red Sox and Los Angeles Angels (6.20 million viewers) and Wednesday’s Game 1 of the National League series between the Los Angeles Dodgers and Chicago Cubs (5.38 million).

Other cable highlights: VH1 scored with Sunday’s season finale of “I Love Money” (1.5/3 in 18-49, 2.93m); FX’s “Sons of Anarchy” held up well (1.1/3 in 18-49, 2.19m) as one of the few cable series not to decline opposite broadcast premieres; and Fox News celebrated its 12th anniversary in style, rising to No. 2 for the week among total viewers and drawing its largest aud to date — 11.10 million for Thursday’s VP debate.

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Monday of the current week saw troubling declines for NBC’s combo of “Chuck” (2.3/6 in 18-49, 5.83m) and “Heroes” (2.2/5, 8.20m). At the same time, CBS was on the rise with all four of its comedies: “The Big Bang Theory” (3.7/10, 9.39m), “How I Met Your Mother” (4.0/10, 8.98m), “Two and a Half Men” (5.1/12, 14.07m) and “Worst Week” (3.0/7, 8.85m).

“Worst Week” will have some direct comedy competish for the first time beginning next week as ABC’s soph skein “Samantha Who?” takes over for “Dancing With the Stars” in the 9:30 half-hour.

Fox’s “Terminator: The Sarah Connor Chronicles” (2.3/6, 5.83m) was up week to week in the 8 o’clock hour and slightly outperformed its struggling lead-out, “Prison Break” (2.2/5, 5.37m).

In Monday’s sports showdown the winner was football (4.6/12 in 18-49, 10.98m for ESPN’s NFL matchup between Minnesota and New Orleans) over baseball (1.9/5, 5.72m for TBS’ game between the Red Sox and Angels).