The final episode of the year for hot rookie “Heroes” combined with another dominant perf by gameshow “Deal or No Deal” to lead NBC to an easy primetime ratings victory on the first Monday in December. The Peacock led the broadcast nets among young adults on a Monday for the 10th time in 12 weeks this season.

According to affiliate-based preliminary nationals from Nielsen, “Deal or No Deal” kicked things off for the Peacock with an easy victory at 8 (5.0 rating/13 share in adults 18-49, 17.2 million viewers overall), doubling the net’s performance on the night a year ago with “Surface.” That led into “Heroes” (6.5/15 in 18-49, 15.0 million viewers overall), as the season’s No. 1 new program delivered winning scores with its fall finale. Net couldn’t maintain its momentum at 10, however, as “Studio 60 on the Sunset Strip” (3.0/8 in 18-49, 7.4 million viewers overall) appears to have delivered its weakest scores to date.

ABC’s numbers are expected to be revised downward in Nielsen nationals, as the net’s preliminary numbers include preemptions for high-rated NFL action on the net’s affils in Philadelphia and Charlotte. In prelims, though, “Wife Swap” (3.4/9 in 18-49, 9.1 million viewers overall) was on the high end, and the season preem of “Supernanny” at 9 performed well (4.0/9 in 18-49, 10.5 million viewers overall. Struggling drama “What About Brian” also was above average at 10 (2.6/7 in 18-49, 6.2 million viewers overall).

At Fox, the “Billboard Music Awards” (2.7/7 in 18-49, 6.0 million viewers overall) ran fourth on the night, coming in more than 10% below last year’s demo delivery on a Tuesday (3.1/8 in 18-49).

CBS, in repeat mode, was paced by “CSI: Miami” (3.7/10 in 18-49, 11.5 million viewers overall) and “Two and a Half Men” (3.4/8 in 18-49, 11.6 million viewers overall).

Preliminary 18-49 averages for the night: NBC, 4.8/12; ABC, 3.3/8; CBS, 2.9/7; Fox, 2.7/8; Univision, 1.3/4; CW, 0.8/2.

In total viewers: NBC, 13.2 million; CBS, 9.4 million; ABC, 8.6 million; Fox, 6.0 million; Univision, 2.8 million; CW, 2.1 million.