Ratings Chart Attack!

“American Idol” made a rare Thursday night appearance, stealing the top spot from “Lost” and giving Fox the nightly win.

“Idol” posted an 8.4 in the 18 to 49 demographic, according to preliminary Nielsen numbers. A new celebrity episode of “Don’t Forget the Lyrics!” rounded out the night with a series-high 4.8, giving Fox a nightly average of 6.6.

It was “Idol’s” lowest-rated results show since another Thursday airing in April 2004.

A new episode of “Lost” was second for the night with a 5.7, down slightly from last week. ABC came in second with a 3.4 for the night.

“Lost” is heading back to a 10 p.m. Thursday slot, as ABC announced “Grey’s Anatomy” will return at 9 p.m. April 24 with a run of five new episodes.

“Lost” made a similar move on Wednesdays last year, which caused some turbulence with its ratings.

ABC is banking on “Grey’s” to increase "Lost's" lead-in (“Grey’s” is guaranteed to do better than the anemic 1.7 the “Lost” repeat posted Thursday), and “Lost” is highly rated in DVR views.

Also in the wings to jump back into the fray on Thursday is “Ugly Betty,” meaning Thursday is returning to its big night status in April (NBC is readying its comedy block, CBS has “Survivor” and is prepping “CSI’s” return in early April, and Fox has “Lyrics” and “Are You Smarter Than a 5th Grader?”).

“Eli Stone” scored a 2.7, similar to last week.

CBS (3.3) took third with a new “Survivor” (4.0) and repeats of “CSI” (3.1) and “Without a Trace” (3.0). "Trace" ended up winning the 10 p.m. slot despite facing original programming.

NBC (1.2) came in fourth with a “My Name Is Earl” repeat (1.7), and new episodes of “Celebrity Apprentice” (3.2) and “Lipstick Jungle” (2.5).

“Apprentice” dipped 13% from last week for one of its lowest showings, but it lacked a “Deal or No Deal” lead-in this week.

The CW brought up the rear in fifth with a repeat (1.0) and a new episode of “Supernatural” (1.3), which tied the show’s season high.