Ratings Chart Attack!

Wednesday night’s two-hour “American Idol” on Fox trounced the competition, sending ABC's “Lost” to its lowest-rated first-run telecast ever.

A special episode of “Idol,” where the top 36 contestants were revealed, scored a 9.4 rating/23 share among adults 18-49 and 24.6 million viewers, according to preliminary Nielsen Media Research figures. The episode was up 2% from the night before, but down 4% from its comparable night last year.

On ABC, a new episode of “Lost” (4.4/10, 9.8 million)—running against the second half of “Idol”—came in as the show’s lowest-rated original episode ever, excluding clip shows.

Down 10% from its previous season average, “Lost” has posted a decrease every week since the show returned last month. In the 10 p.m. hour, a new “Life on Mars” (1.9/5, 5.1 million) pulled in its lowest rating to date. Kicking things off with an encore of “Lost” (1.6/4, 4.4 million), the network finished third with a 2.6/7 (6.4 million).

New comedies and dramas on CBS gave the network second place for the night, averaging a 2.9/7 (11 million). “The New Adventures of Old Christine” (1.9/5, 7.1 million) was down about 10% from its last original episode. “Gary Unmarried” (2.1/5, 6.9 million) and “Criminal Minds” (3.3/8, 13.3 million) both performed below their previous season averages, while “CSI: NY” (3.4/9, 12.8 million) was average.

NBC placed fourth with a 1.6/4 (5.9 million) for the night. New episodes of “Knight Rider” (1.3/3, 5.4 million), “Life” (1.4/3, 4.7 million) and “Law & Order” (2.1/6, 7.5 million) showed declines from last week, each down 7%, 22% and 13%, respectively, in the demo.

The CW aired repeats of “Privileged” (0.5/1, 1.1 million) and “90210” (0.4/1, 0.9 million). The network averaged a 0.4/1 (1 million) in the demo, and a 0.7/2 among women 18-34.