Viewership for "The Big Bang Theory" was up substantially this summer, a trend that continued against tougher competition when the new television season began in September.

The comedy drew what was its best-ever audience of 12.96 million viewers for its season premiere on Sept. 21, topping that with 13.27 million viewers a week later.

CBS' usual stalwarts made it the most-watched network for the fifth time in the season's five weeks, averaging 10.74 million viewers for its prime- time programming between Oct. 19 and Sunday.

For the fifth consecutive week, CBS had the most-watched program, "NCIS," and the most-watched new series -- its spin-off "NCIS: Los Angeles."

Fox Broadcasting was second, averaging 10.28 million viewesr, thanks almost exclusively to its sports programming. Sunday's decisive Game 6 of the American League Championship Series between the Los Angeles Angels of Anaheim and the New York Yankees was fourth for the week with 15.48 million viewers, while Game 5 on Thursday was 19th with 11.85 million.

Fox also benefited from a nearly hourlong runover of its afternoon NFL coverage into prime time, which averaged more than 25 million viewers.

ABC was third for the week, averaging 9.06 million viewers, followed by NBC with 7.24 million and The CW with 1.95 million.

Fox was first for the week among viewers ages 18-49, the advertiser- coveted group it targets, along with ABC and NBC.

NBC's "Sunday Night Football" game between the Arizona Cardinals and New York Giants was the week's most-watched program in the 18-49 group despite finishing seventh among all viewers.

Fox also led among viewers ages 12-17, 18-34 and 25-54, while CBS was first as usual among viewers ages 55 and older.

For ratings purposes, ABC and CBS aired 22 hours of prime-time programming during the week; NBC 21 1/2; Fox 18 hours, 43 minutes; and The CW 10.

The ESPN "Monday Night Football' game between the Denver Broncos and San Diego Chargers was the week's most-watched cable program with 13.47 million viewers, which would have placed it 14th among the programs on the five major broadcast networks.

ESPN was cable's most-watched network in prime time for the seventh time in eight weeks, averaging 3.77 million viewers. NBC had the most-watched network nightly newscast for the 53rd time in 54 weeks, averaging 8.28 million viewers.

ABC's telecast was second, averaging 7.69 million viewers, while "The CBS Evening News with Katie Couric" averaged 5.97 million viewers to finish third for the 161st consecutive week.

As usual, Univision was the most-watched Spanish-language network, averaging 3.53 million viewers for its prime-time programming. Telemundo was in its customary second-place position, averaging 1.06 million, followed by Telefutura with 790,000 and Azteca America with 200,000.

The week's most-watched Spanish-language prime-time program was the Wednesday edition of the Univision telenovela "Sortilegio," which averaged 5.47 million viewers, which would have put it 63rd among programs on the five major English-language networks.

The week's 10 most-watched prime-time programs were CBS' "NCIS"; the Monday edition of ABC's "Dancing with the Stars"; CBS' "NCIS: Los Angeles"; Fox Broadcasting's coverage of Game 6 of the American League Championship Series between the Los Angeles Angels of Anaheim and New York Yankees and its 10-minute football post-game show, "The OT"; ABC's "Grey Anatomy"; NBC's "Sunday Night Football" game between the Arizona Cardinals and New York Giants; the "Dancing with the Stars" results show; CBS' "Criminal Minds"; and ABC's "Desperate Housewives."