Fox notched another Tuesday victory in key demo categories this week behind big numbers for “American Idol” and a solid showing by “24,” according to preliminary nationals from Nielsen. NBC’s “Frasier” also looked good as it nears its series finale next week.

In the opening hour, “American Idol” (8.7/26 in adults 18-49, 22.0 million viewers overall) dominated the competish, although stepped-up sweeps competish helped bring its numbers down a bit from recent weeks. Lead-out drama “24” (4.9/13 in adults 18-49, 11.4 million viewers overall) was in a tight battle with NBC’s comedies for the 18-49 lead from 9 to 10.

At NBC, “Frasier” grabbed its best ratings in seven months (5.2/14 in adults 18-49, 13.8 million viewers overall), leading its slot in several key categories. The season finale of “Scrubs” followed (4.8/12 in adults 18-49, 11.1 million viewers overall) with its first 18-49 slot victory in 11 weeks, retaining 92% of its “Frasier” lead-in and building on “Frasier” by 18% in adults 18-34.

“Law & Order: SVU” closed things out for NBC with another victory at 10 (5.4/14 in adults 18-49, 13.3 million viewers overall).

Both ABC and CBS were led by their 10 o’clock dramas, “NYPD Blue” (3.6/10 in adults 18-49, 9.7 million viewers overall) and “Judging Amy” (2.9/8 in adults 18-49, 11.8 million viewers overall), respectively.

Preliminary 18-49 averages for the night: Fox, 6.8/19; NBC, 4.2/12; ABC, 3.1/8; CBS, 2.3/6; WB, 1.9/5; UPN, 0.9/3.

In total viewers: Fox, 16.7 million; NBC, 10.8 million; CBS, 10.5 million; ABC, 8.2 million; WB, 4.5 million; UPN, 2.5 million.