After being preempted for two weeks by college basketball, the CBS Thursday lineup scored a ratings victory in key demos this week powered as usual by “CSI.”

According to preliminary nationals from Nielsen, “CSI” (7.9 rating/20 share in adults 18-49, 25.1 million viewers overall) was Thursday’s top program despite numbers on the low end of its ratings range. “Survivor: Exile Island” easily won at 8 (5.9/17 in 18-49, 16.5 million viewers overall) and was above its recent scores when it went up against “American Idol.” At 10, “Without a Trace” (5.6/15 in 18-49, 18.3 million viewers overall), like “CSI,” was on the low side but tied or led its slot in most key categories.

“ER,” also on the low side but in line with its recent firstrun scores, paced NBC (5.6/15 in 18-49, 13.0 million viewers overall), tying “Trace” for the 18-49 lead at 10. “Will & Grace” opened the night in second place (3.6/11 in 18-49, 9.3 million viewers overall), and “My Name is Earl” kept the net in the runner-up position to “CSI” at 9 despite its lowest firstrun score to date. “The Office” (4.1/10 in 18-49, 8.0 million viewers overall) again held on to most of its “Earl” lead-in, tying for the second in 18-49.

ABC’s unscripted series “American Inventor” (3.7/9 in 18-49, 9.3 million viewers overall) declined 27% week to week opposite regular competish on CBS. Still, this is a good score for ABC in the hour, and “Inventor” fared better relative to last week than 8 o’clock skein “Extreme Makeover: After the Storm” (2.2/6 in 18-49, 7.4 million viewers overall), which tumbled nearly 40%.

Fourth-place Fox was paced by “The OC” (2.6/7 in 18-49, 5.5 million viewers overall), which was up a tick week to week.

Preliminary 18-49 averages for the night: CBS, 6.5/17; NBC, 4.5/12; ABC, 2.9/8; Fox, 2.4/6; WB, 1.7/5; UPN, 0.8/2.

In total viewers: CBS, 20.0 million; NBC, 10.2 million; ABC, 7.8 million; Fox, 5.0 million; WB, 4.1 million; UPN, 2.0 million.