There seems to be nothing stopping CBS now ... not even "American Idol" on Fox.

The network won its 20th week in 28 tries Friday, led by shows such as "NCIS" and "NCIS: Los Angeles," and not letting a lower-than-expected performance from "Gary Unmarried" get in its way.

CBS averaged a 7.2 rating/12 share in Fast National ratings from The Nielsen Co. last week, in ratings that include only first-run, non-news, non-event programming. That means ratings didn't include NCAA basketball, considered even-programming, which likely would've brought the network's ratings down.

It beat out Fox once again, which finished with a 5.7/9, despite three airings of "American Idol." However, it was the network's need to burn off "Til Death" in the middle of the regular season that's bringing those numbers down. Two episodes of that show Sunday earned a 1.2/2. Without that airing, Fox would've finished with a 6.6/11 ... still not enough to beat CBS, but bringing it a lot closer.

Fox also struggled with its new comedy series "Sons of Tucson," which earned a 2.6/4, less than what the Friday edition of "Kitchen Nightmares" earns. Eliminating both "Til Death" and "Sons of Tucson" would've given Fox a 7.1/12 finish, which would've handed CBS a very slim victory.

NCAA basketball on CBS didn't have much of an impact on other shows on the network, except to have many of them go up in audiences. One of the few shows that didn't see an increase was "FlashForward" on ABC, which continued its ratings downtrend after a 105-day break.

CBS still leads four of six nights in the broadcast week, with ABC still leading Mondays thanks to both "Dancing With the Stars" and "The Bachelor" and Fox winning Wednesdays behind its "American Idol" offerings.

Top 10 Network Shows, Week of March 14 -- [Audience Loyalty Index rating]
1. (1) American Idol (Fox) -- 13.3/21 -- [83.3]
2. (3) American Idol (Fox) -- 12.3/20 -- [90.0]
3. (4) American Idol (Fox) -- 11.6/19 -- [80.4]
4. (2) NCIS (CBS) -- 10.9/18 -- [93.8]
5. (6) NCIS: Los Angeles (CBS) -- 9.4/14 -- [91.0]
6. (10) The Good Wife (CBS) -- 8.6/15 -- [91.6]
7. (-) Undercover Boss (CBS) -- 7.7/12 -- [55.4]
8. (-) Desperate Housewives (ABC) -- 7.3/11 -- [88.0]
9. (13) House (Fox) -- 6.7/11 -- [80.6]
10. (-) Cold Case (CBS) -- 6.3/11 -- [92.1]

Top Networks, Week of March 14 -- [ALI]
1. (1) CBS -- 7.2/12 -- [66.1]
2. (2) Fox -- 5.7/9 -- [42.9]
3. (3) ABC -- 4.5/7-- [61.6]
4. (4) NBC -- 4.2/7 -- [67.7]
5. (5) The CW -- 1.5/2 -- [57.7]

Top 15 Network Shows, Season
1. (1) American Idol (Fox), Tues (9) -- 14.0/20
2. (2) American Idol (Fox), Tues (8) -- 13.5/21
2. (3) American Idol (Fox), Wed (8) -- 13.5/21
4. (4) American Idol (Fox), Wed. 9 -- 12.7/20
5. (5) NCIS (CBS) -- 12.1/19
6. (6) Dancing With the Stars (ABC), Mon (9) -- 11.6/17
7. (7) Dancing With the Stars (ABC), Mon (8) -- 11.1/17
8. (9) American Idol (Fox), Thurs (8) -- 10.7/17
9. (8) Undecover Boss (CBS) -- 10.3/16
10. (10) NCIS: Los Angeles -- 10.1/16
11. (11) Dancing With the Stars (ABC), Wed -- 9.8/16
12. (12) Dancing With the Stars (ABC), Tues -- 9.7/15
13. (13) The Mentalist (CBS) -- 9.6/16
14. (14) CSI (CBS) -- 9.5/15
15. (15) Two and a Half Men (CBS) -- 9.1/13

Top Networks, Season
1. (1) CBS -- 7.3/12
2. (2) ABC -- 5.4/9
3. (3) Fox -- 4.9/8
4. (4) NBC -- 4.2/7
5. (5) The CW -- 1.6/3

Fast Nationals usually provide a snapshot of what Americans are watching by pulling numbers from the top urban markets that includes both live viewing and same-day timeshifted viewing. A rating point generally represents more than 1.1 million households while the share indicates the percentage of televisions turned on that was tuned to the specific program. These numbers typically shift when final ratings are issued.

Data collected from The Nielsen Co., as distributed by Zap2it. BlipNetwork tracks non-news, non-event programming, and figures for this story reflect airing of new episodes only. For more information on the Audience Loyalty Index, click here.