Fast National ratings for Tuesday, Jan. 20, 2009.

FOX's "American Idol" lost roughly 8 million viewers from its premiere last week, while "Fringe" struggled to hold onto its lead-in. Neither fact prevented FOX from winning the night.

FOX averaged a 6.8 rating in the 18-49 demographic, beating the 3.4 rating averaged by ABC and NBC in the key age group. CBS was fourth with a 2.2 rating, while The CW's 0.9 rating trailed.

Overall, FOX averaged an estimated 17.26 million viewers for the night with a 9.6 rating/14 share. ABC was an acceptable second with a 7.3/11, while CBS took third with a 6.1/9. NBC's 5.5/8 was good for fourth, while The CW's 1.4/2 stood in fifth.

In the 8 p.m. hour, FOX's "American Idol" averaged 22.42 million viewers and a 12.1/18. ABC's inaugural coverage was second with an 8.0/12. CBS' "NCIS," which held up well against "Idol" last week, did a 7.3/11 with a repeat. NBC's "Biggest Loser: Couples" was fourth, while The CW's "90210" was fifth with a 1.5/2.

ABC's "Neighborhood Ball" coverage of the inauguration won the 9 p.m. hour with a 7.9/12. NBC's "Biggest Loser" was second with a 7.3/11. "Fringe" averaged a 7.1/10 for the hour, but it fell to a 6.4/9 in its second half-hour. CBS' inaugural coverage was fourth, while The CW's "Privileged" bounced back from last week's totals with a 1.2/2.

CBS moved into first at 10 p.m. with the 6.6/11 for "The Mentalist." ABC's news special was second with a 6.2/10 while "Dateline NBC" trailed.

All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.