Ratings Chart Attack!

ABC’s season premiere of “Dancing With the Stars” waltzed its way to a strong debut, taking down some heavyweights on the other broadcast networks.

The two-hour season opener averaged a 5.9 rating/15 share among viewers 18-49 and 22.5 million viewers, according to preliminary Nielsen Media Research numbers. Last night’s “Dancing” posted gains over previous premieres of the competition series, up 9% from last fall’s debut and 5% from last spring’s; it ranks as the most-watched and second highest-rated.

At 10 p.m. ABC’s new series “Castle” kicked off with a 3.3/9 (11.6 million), down 44% from its “Dancing” lead-in. That drop-off, however, is similar to last year’s debut of “The Bachelor: London Calling,” which pulled in the same rating in the post-“Dancing” timeslot. Although “Castle” also lost 22% of its audience from first half-hour to second, the telecast improved the network’s time-period average by 18%. Overall, ABC finished first with a 5.1/3 (18.9 million), which ranks as the network’s biggest audience since May 2006.

Fox finished second with a 4.2/11 (11.7 million) for the night. A new “House” scored a 4.8/11 (12.1 million), down 13% from its most recent episode two weeks ago to score its lowest-rated original telecast since December 2004. A new “24” ticked its way to a 3.6/9 (11.3 million), up 9% from its two-hour special last week.

“Dancing” held off new episodes of CBS’ comedies, and the network finished third for the night with a 4.0/10 (11.6 million). “The Big Bang Theory” (3.6/10, 9.5 million) and “How I Met Your Mother” (3.5/9, 8.5 million) were down 8% and 17%, respectively, from last week. “Two and a Half Men” (4.7/11, 13.3 million) was down 4% from last week, while “Rules of Engagement” (3.7/9, 10 million) was down 5% from its season premiere last week. At 10 p.m., “CSI: Miami” (4.3/11, 14.1 million), posted a 13% week-to-week increase.

NBC also felt the brunt of “Dancing’s” power from 8-10 p.m., as both “Chuck” and “Heroes” hit series lows. “Chuck” scored a 2.0/5 (5.7 million), down 17% from last week and 20% from its season-to-date average. “Heroes” continued its downward trend, scoring a 3.2/8 (6.6 million), off 18% from its season average. At 10 p.m., “Medium” (2.5/6, 7.1 million) was up a tick from last week’s performance. The network finished fourth with a 2.5/7 (6.5 million).

The CW aired repeats of “Gossip Girl” and “One Tree Hill” to the tune of a 0.5/1 (1.2 million), averaging a 0.8/2 among women 18-34.