It was another broadcast-net logjam in Thursday’s middle hour, with ABC’s “Grey’s Anatomy,” CBS’ “CSI” and NBC’s “The Office” posting the night’s top three ratings among adults 18-49. The Alphabet net pulled out ahead in adults 18-49, while CBS led in adults 25-54 and total viewers.

According to preliminary nationals from Nielsen, “Grey’s Anatomy” (roughly 7.8/19 in 18-49, 18.9 million viewers overall from 9 to 10:03 p.m.) was up week to week and opened up a wider advantage over the potent “CSI” on CBS (6.0/14 in 18-49, 19.6 million viewers overall) and “The Office” on NBC (4.7/11 in 18-49, 8.9 million viewers overall). “Grey’s” won the hour in 18-49 and 25-54 and dominated in key female demos while “CSI” prevailed in total viewers and “The Office” led in men 18-34.

Opening the night, CBS remained victorious with “Survivor: China” (4.5/13 in 18-49, 14.0 million viewers overall), which was flat week to week while its closest pursuer, ABC’s “Ugly Betty” (3.5/10 in 18-49, 10.4 million viewers overall), was up a tick and again led the hour in adults 18-34. NBC’s “My Name Is Earl” was on the low end (3.1/9 in 18-49, 7.7 million viewers overall), while “30 Rock” held onto nearly all of its demo lead-in at 8:30 (3.0/8 in 18-49, 6.6 million viewers overall).

It was another tight demo battle at 10, with ABC rookie “Big Shots” (roughly 3.6/10 in 18-49, 8.4 million viewers overall from 10:03 to 11 p.m.) running neck and neck with CBS vet “Without a Trace” (3.6/10 in 18-49, 13.6 million viewers overall), which easily drew the most viewers overall. NBC’s “ER” (3.4/10 in 18-49, 8.4 million viewers overall) trailed them both but pulled into a tie for the 18-49 lead at 10:30.

Fox ran fourth both at 8 with “Are You Smarter Than a 5th Grader” (2.3/7 in 18-49, 8.2 million viewers overall) and in the brutal 9 o’clock hour with “Don’t Forget the Lyrics” (1.8/4 in 18-49, 5.6 million viewers overall). Similarly, CW was respectable at 8 with “Smallville” (1.9/5 in 18-49, 4.8 million viewers overall) and then slid at 9 with “Supernatural” (1.2/3 in 18-49, 3.2 million viewers overall).

Preliminary 18-49 averages for the night: ABC, 5.0/13; CBS, 4.7/12; NBC, 3.7/10; Fox, 2.1/5; Univision, 1.6/4; CW, 1.5/4.

In total viewers: CBS, 15.8 million; ABC, 12.8 million; NBC, 8.2 million; Fox, 6.9 million; CW, 4.0 million; Univision, 3.7 million.