After encouraging first 2 weeks on Friday, Fox’s Fringe (1.6/5 in 18-49, 4.2 million viewers) dropped 16% in the demo in its third airing against an original Supernatural and a Super Bowl commercials special on CBS. At 8 PM, Kitchen Nightmares (1.7/6, 4 million) held steady and won the hour in the demo.

CBS’ The Defenders (1.3/4, 8.7 million) expectedly hit an all-time low in its first airing on Fridays. Its predecessor in the 8 PM slot, Medium, used to draw about a 1.4 demo rating. Like The Defenders, CBS’ annual Super Bowl’s Greatest Commercials special (2.0/6, 9.5 million) relocated from Wednesday to Friday this year and shed a third of last year’s demo result (2.9/9, 11 million on Feb. 3, 2010) but still finished as the highest-rated program on the night in 18-49. At 10 PM, CSI: NY (1.9/6, 9.3 million) was up 12% in the demo from its last original in the 9 PM slot.

The season premiere of NBC’s unscripted series Who Do You Think You Are delivered a 1.3/4 in 18-49 and 7.3 million viewers. It was down in the demo from last season’s premiere after the Olympics (1.6/6 in 18-49, 6.9 million) but hit a series high in total viewers. A two-hour Dateline (1.9/6, 8.6 million) was up 12% from last week for season highs in 18-49 and viewers.

ABC’s Supernanny (1.2/4) was up a tenth from its last original 2 weeks ago.  Primetime: What Would You Do? (1.3/4) was flat with last Friday, while Barbara Walters’ special at 10 PM (1.1/3) was the lowest-rated program on the Big 4, barely edging the CW dramas.

Speaking of CW’s sci-fi series, after a week delay, they finally returned to originals last night. Smallville (2.4 million, 1.0/3 in 18-49, 0.9/3 in 18-34) was flat in 18-49 with its last original on Dec. 10 and down a tenth in 18-34. Supernatural (1.0/3, 2.3 million, 1.1/4 in 18-34) was even with its last original in December in 18-49 and slightly up in viewers and 18-34.