Last night the debut of "The Biggest Loser 5" delivered the heftiest Nielsen rating ever for a "Biggest Loser" premiere, according to "fast affiliate-based" "live plus same day" viewing figures from Nielsen Media Research.

Last night from 8-10 p.m. ET, "The Biggest Loser 5" (4.3 rating, 10 share in adults 18-49, 10.4 million viewers overall) surged by 39 percent in 18-49 rating and by 33 percent in total viewers versus the premiere telecast of the most recent cycle (a 3.1/9 in 18-49 and 7.8 million viewers overall from 8-10 p.m. on Tuesday, Sept. 11, 2007). "The Biggest Loser" was the #1 non-sports program in its time period last night in adults 18-49 and total viewers and ranked #1 outright in all key adult-female demographics.

Excluding finales, this is the top-rated "Biggest Loser" telecast in adults 18-49 since the penultimate telecast of the first "Biggest Loser" cycle on January 4, 2005.

From its first half-hour to its fourth, "Biggest Loser" gained 67 percent in 18-49 rating (to a 5.5/12 from a 3.3/8) and its overall viewership increased by 4.2 million persons, or 50 percent (to 12.7 million from 8.5 million).

From 10-11 p.m. ET, "Law & Order: Special Victims Unit" (4.2/11 in 18-49, 12.3 million viewers overall) is currently tied for #1 in adults 18-49 with Fox's college football telecast, pending updates, and ranks #1 outright in total viewers and all key adult-female demographics.

Preliminary 18-49 averages for Tuesday night are: Fox, 4.7/11; NBC, 4.3/10; ABC, 2.2/5; CBS, 1.9/4; CW, 0.5/1. In overall total viewers, January 1 preliminary results are: Fox, 11.9 million; NBC, 11.1 million; CBS, 8.4 million; ABC, 6.3 million; CW, 1.4 million

Note that all national ratings are "live plus same day" unless otherwise indicated.