A monster season premiere for ABC's hot "Grey's Anatomy" helped the net capture the opening Thursday of the television season in key demos, while another medical skein, NBC vet "ER," ruled over a pair of new dramas in the evening's final hour.

According to preliminary nationals from Nielsen, "Grey's Anatomy" made its firstrun Thursday bow a smashing success, winning the head-to-head battle with CBS crime vet "CSI" in both adults 18-49 (10.9/26 to 7.5/18) and adults 25-54 (11.7/25 to 9.3/20). And in something of a surprise, the Alphabet drama also won in total viewers (25.1 million to 22.0 million).

"Grey's" was up 26% in adults 18-49 vs. its September 2005 season premiere in 18-49 (8.3/20) and rose 10% over its May 2006 season finale (9.9/22). "CSI" put up a number that will likely leave it the No. 3 drama of the week in 18-49, although it declined 26% from last season's premiere (10.2/25) and 10% from May's finale (8.3/20). Also in the 9 o'clock hour, NBC's "Deal or No Deal" was a distant third (3.5/9 in 18-49, 10.2 million viewers overall), declining 24% from "The Apprentice" in the slot last year (4.6/11).

"ER" opened its 13th season a winner in key demos at 10 (6.8/18 in 18-49, 15.6 million viewers overall) and also prevailed in total viewers despite huge lead-in advantages for ABC and CBS. ABC rookie "Six Degrees" was runner-up (5.8/15 in 18-49, 13.3 million viewers overall) but lost a significant chunk of its initial audience in the second half-hour. CBS was also less-than-impressive in the hour with new James Woods drama "Shark" (4.2/11 in 18-49, 15.0 million viewers overall), which also declined on the half-hour.

"ER," which nearly doubled its lead-in among adults 18-49, rose 6% over its year-ago premiere (6.4/16).

In the night's opening hour, CBS ruled with "Survivor: Cook Islands" (6.4/18 in 18-49, 17.3 million viewers overall), which was on par with its week-earlier premiere and up vs. the same night a year ago. ABC was a solid No. 2 with a "Grey's Anatomy" clipshow (4.8/13, 13.5 million viewers overall), with NBC running third with comedies "My Name Is Earl" (3.7/11 in 18-49, 8.9 million viewers overall) and "The Office" (4.3/11 in 18-49, 9.1 million viewers overall); this was the largest build to date for "The Office" on "Earl."

Fox was an afterthought once again with its listless laffers "Til Death" (2.2/7 in 18-49, 5.9 million viewers overall) and "Happy Hour" (1.7/4 in 18-49, 4.4 million viewers overall). And 9 o'clock unscripted skein "Celebrity Duets" fared even worse (1.2/3 in 18-49, 3.3 million viewers overall).

Compared to the opening Thursday a year ago, ABC more than tripled its 18-49 audience, while CBS was down about 20%, NBC was up nearly 10% and Fox tumbled about 40%.

Preliminary 18-49 averages for the night: ABC, 7.2/19; CBS, 6.0/15; NBC, 4.8/12; Fox, 1.6/4; In total viewers: CBS, 18.1 million; ABC, 17.3 million; NBC, 11.6 million; Fox, 4.2 million; CW, 2.4 million.