Ratings Chart Attack!

NBC stumbled Monday, with each of its shows, including the embattled “Heroes,” posting or matching ratings lows for original episodes.

“Chuck” ended the night with a 2.3 rating/6 share in the 18- to 49-year-old demographic, according to preliminary Nielsen Media Research data. The show declined 12% from its last original episode two weeks ago.

“Heroes” continues its slow descent with a 3.6/8, down 7% from two weeks ago to a series low. NBC is quick to point out that “Heroes” does see a 20% increase with the release of live-plus-7 data, which factors in a week’s worth of DVR views.

“My Own Worst Enemy” (1.8/5) took the biggest tumble, dropping off by 22%. “Enemy” has lost ground and has held a smaller amount of its “Heroes” lead-in with each airing, keeping just half of the audience yesterday.

NBC ended the night with a 2.6/6, putting it in third.

CBS returned as king of the hill in adults 18-49 on Monday with its comedy block, as “The Big Bang Theory” (3.9/10, 10 million), “Two and a Half Men” (4.9/11, 14.6 million) and “Worst Week” (2.9/7, 9.6 million) crept up slightly from last week, showing 8%, 7% and 12% week-to-week improvements. “How I Met Your Mother” (4.1/10, 9.7 million) held steady, while “CSI: Miami” (3.7/10, 13.7 million) ticked up one tenth of a ratings point.

CBS took first in 18-49 with a 3.9/10 and second in total viewers with 11.9 million.

ABC’s “Dancing With the Stars” (4.2/10, 18.8 million) was in line with recent telecasts, but down 19% from last year at this time.

Both “Samantha Who?” (3.0/7) and “Boston Legal” (2.3/6) gained considerably from last week, growing a respective 25% and 28% from last week. ABC was second in 18-49 with a 3.4/8 and first in viewers with 14.1 million for the night.

There wasn’t much activity for Fox’s “Terminator: The Sarah Connor Chronicles” (2.0/5) and “Prison Break” (2.2/5), with both falling near last week’s showing. Fox took fourth place for Monday with a 2.1/5.

The CW saw declines across the board, but the network was preempted in San Francisco for football, which contributed to the slips. “Gossip Girl” (1.5/4) dipped 13% in women 18-34, the network’s key demographic, ending with a 3.4/9. “One Tree Hill” (1.6/4) also declined, slipping 5% to a 3.6/9 in women 18-34.

Despite the declines, The CW brought in its ninth seasonal win on Monday in the women 18- to 34-year-old demographic.