Strong showings Monday and Sunday bookended NBC’s week as the Peacock notched its second demo victory of the season.

While “Sunday Night Football” and Monday’s “Deal or No Deal” and “Heroes” were all big contributors, the net also saw its Thursday comedies and Friday’s “Las Vegas” produce.

NBC delivered year-to-year demo gains for the sixth straight week and is up 12% in adults 18-49 through 11 weeks of the season; its rivals are all down by single-digit percentages, according to Nielsen estimates. It was also a good week for the CW, as the newbie net established highs thanks to fall-best ratings for its core skeins.

Overall for the Nov. 27-Dec. 3 frame, the Peacock’s 3.7 rating/10 share in adults 18-49 bested ABC (3.5/9), CBS (3.4/9) and Fox (3.2/9), with the latter more competitive than usual thanks to football coverage on its winning Sunday. The CW and Univision tied for fifth (1.5/4).

CBS led in adults 25-54 for the 10th time this season (4.4/11), edging out NBC (4.3/10), while Fox edged out the balanced Peacock for the lead in viewers 12-34 (2.8/9 to 2.7/8).

CBS ruled in total viewers (11.8 million), extending its season-opening winning streak to 11 weeks.

For NBC, “Heroes” (6.8 rating/16 share in adults 18-49, 15.56 million viewers overall) led the way, ranking as the No. 3 show on television in the 18-49 demo — trailing only ABC’s “Grey’s Anatomy” and Fox’s “House.” Show’s delivery was its second-best to date.

“Deal or No Deal” also dominated its Monday hour (5.3/13, 17.70m), and the net closed the week with another top-10 finish from “Sunday Night Football” (5.6/14, 15.42m).

Also of note was the net’s good showing Thursday with the return of a four-comedy lineup.

“The Office” (4.4/11 in 18-49, 9.07m) hit a season high, building on lead-in “My Name Is Earl” (4.1/11, 9.49m), and “Scrubs” (3.6/9, 7.72m) held up opposite tough competish at 9 with its season premiere. At 9:30, “30 Rock” (2.7/7, 5.97m) did OK.

“ER” led its Thursday hour (5.8/15, 13.36m), and “Las Vegas” hit a season high Friday with a two-hour seg (3.2/10, 10.16m).

The CW delivered its best week yet in adults 18-34 (1.8/5) and total viewers (3.8 million), thanks to some strong perfs on the closing night of sweeps.

Driving the strong week were fall highs for the Tuesday combo of “Gilmore Girls” (2.2/6 in 18-49, 4.89m) and “Veronica Mars” (1.6/4, 3.44m). “Veronica,” a third-year drama that had aired previously on UPN, delivered its best ratings ever in adults 18-34 (2.0/5).

There also were season bests on Wednesday for “America’s Next Top Model” (2.8/8, 5.73m) and “One Tree Hill” (1.8/5, 4.15m), with the former WB skein logging its best numbers in two seasons.

Net also was high with its Monday laffers, Friday’s “WWE Smackdown” (1.5/4 in 18-49, 4.72m) and Sunday’s “7th Heaven” (1.6/4, 4.23m).

At ABC, highlights included Thursday’s “Grey’s Anatomy” (9.5/23 in 18-49, 24.01m), the week’s No. 1 primetime program in most categories. Net also was solid on the night at 8 with “Ugly Betty” (4.1/11, 13.02m) and was above average at 10 with “Men in Trees” (3.8/10, 11.34m), making its new-slot debut.

Friday’s network preem of “The Polar Express” was a big draw (4.1/12 in 18-49, 13.21m), delivering the best numbers for a theatrical movie on broadcast television since February 2004 (“Shrek” on NBC). Pic did a big 6.4/20 in kids and won in most key ratings categories.

Also, Monday’s “Wife Swap” (3.4/9 in 18-49, 8.87m) and “The Bachelor: Rome” (3.9/9, 9.85m) hit season highs, and Tuesday’s airing of “A Charlie Brown Christmas” (4.8/13, 13.01m) was a winner. Its lead-out, comedy “Big Day,” didn’t do much in its premiere, though (2.8/7, 7.55m).

CBS was paced by “CSI: Miami” (5.7/14 in 18-49, 17.13m), “Survivor” (5.4/14, 15.63m) and “CSI: NY” (5.2/14, 17.92m). Also performing above average were “CSI: NY” Wednesday skedmates “Jericho” (3.1/9 in 18-49, 10.25m for its fall finale) and “Criminal Minds” (5.0/13, 17.92m).

And Tuesday’s “NCIS” (4.1/11 in 18-49, 17.96m) hit season highs in both adults 25-54 (5.8/14) and total viewers, ranking as the No. 2 program of the week in the latter.

Fox benefited from the concluding 25 minutes of coverage for the late-afternoon Dallas Cowboys-New York Giants game (11.4/33 in 18-49), as the contest averaged 27.6 million viewers overall, making it the week’s most watched program. Also Sunday, an 8 o’clock half-hour spec detailing the college football bowl matchups notched a solid 5.4/14 in 18-49.

Entertainment series standouts for the net were “House” (6.9/17, 17.30m), which hit a fall high, and “Prison Break” (4.0/10, 9.62m), which was above average with its fall finale.

ESPN led the primetime cable ratings race thanks to “Monday Night Football” (5.2/13 in 18-49, 12.70m for Seahawks-Packers), while TNT original movie “The Librarian: Return to King Solomon” (2.2/5, 6.17m) was the week’s No. 2 cablecast.

Of note on Saturday was Hallmark Channel’s original movie “The Christmas Card” (0.8/3 in 18-49, 4.27m), which logged the largest overall aud to date for the net and was the day’s most-watched cable program.

On Sunday, ABC Family got its “25 Days of Christmas” off to the best start in its nine-year history thanks to the premiere of “Harry Potter & the Prisoner of Azkaban” (1.0/3 in 18-49, 2.83m). Pic propelled the net to its highest-rate day to date in key demos and total viewers.

And on Monday of the current week, TNT’s special two-hour seg of drama “The Closer” drew a sizable 5.44 million viewers.