Ratings Chart Attack!

“American Idol’s” top 13 contestants sang their way to a ratings win for Fox Tuesday night.

Last night’s two-hour “Idol” scored a 9.2 rating/24 share among adults 18-49 and 25.2 million viewers, according to preliminary Nielsen Media Research figures. The show was up 2% from last week, but dipped 16% from the comparable night last year. (For the week so far, “Idol” edged out Monday’s premiere of “Dancing With the Stars” by about 2.4 million viewers, vs. “Dancing’s” final viewership average.)

NBC took second place (3.7/10, 9.9 million) with new episodes of “The Biggest Loser” (3.8/10, 9.3 million) and “Law & Order: SVU” (3.6/20, 11 million). “Loser” scored the network’s best rating in the demo while up against a regular two-hour “Idol,” excluding Olympics coverage, and the show’s highest in five weeks. “Loser” also posted a 9% gain from last week and a 27% increase from last year, when the show also was up against “Idol.” At 10 p.m., “SVU” won the hour while also logging the show’s biggest audience for the season to date.

CBS aired repeats of “NCIS,” “The Mentalist” and “Without a Trace” and landed in third place for the night, averaging a 2.5/7 (12.6 million).

On ABC, a new episode of “Homeland Security U.S.A.” (1.4/4, 5.1 million) opened the night, followed by back-to-back repeats of “Scrubs” and a new “Primetime: What Would You Do?” (1.9/5, 5.1 million), which came in low. ABC finished fourth with a 1.5/4 (4.4 million).

The CW finished fifth with a 0.6/2 (1.6 million). A new episode of “Reaper” (0.8/2, 2.2 million) was down a tick from its season premiere last week. A repeat of “90210” aired in the 9 p.m. hour. The network averaged a 0.8/2 among women 18-34 for the night.