Fast National ratings for Tuesday, Sept. 30, 2008

"The Mentalist" remained strong for CBS Tuesday, helping the network claim the biggest share of viewers for the night. FOX and "House," however, dominated the demographic race.

CBS averaged a 9.7 rating/15 share in primetime, defeating FOX, 7.0/11, by a good-sized margin. ABC came in third at 5.9/9, a little ahead of NBC's 5.5/9. The CW finished well out of the running at 1.8/3.

In the adults 18-49 demographic, FOX scored the victory with a 4.8 rating. CBS and NBC tied for second at 3.2. ABC averaged 2.4 and The CW 1.3.

"NCIS" put CBS on top at 8 p.m. with a 10.9/17, topping the 7.8/12 for "House" on FOX (the latter show won the hour in the 18-49 demo). "The Biggest Loser: Families" earned a 4.5/7 for NBC. "Opportunity Knocks" was fourth for ABC, and "90210" delivered a 2.2/3 for The CW.

At 9 p.m., ABC's "Dancing with the Stars" results show led in households with a 10.0/15, but "The Mentalist," 9.7/15, brought a few more viewers to CBS. "Fringe" drew a 6.2/9 for FOX and kept the network on top among adults 18-49. "The Biggest Loser" improved to 5.0/8 in its second hour on NBC. "Privileged" finished the night for The CW.

CBS led at 10 p.m. thanks to "Without a Trace," 8.5/14. "Law & Order: SVU" scored a 6.9/12 for NBC, while ABC faded badly, managing only a 3.7/6 with a weight-loss special called "Half Their Size."

Ratings information is taken from fast national data, which includes live and same-day DVR viewing. All numbers are preliminary and subject to change.