Fast National ratings for Thursday, March 4, 2010.
 
A special hour-long episode of "The Office" helped make NBC a surprise demo winner in the competitive 9 p.m. hour, but it was "American Idol" and "CSI: Crime Scene Investigation" generating Thursday's biggest audiences.
 
Meanwhile, in its second airing (and time-slot premiere), "The Marriage Ref" took a big audience plunge, but still won its hour in the 18-49 demo.
 
Among adults 18-49, FOX won Thursday with a 4.9 rating, beating the 3.6 for CBS and the 3.5 for NBC in the key demographic. ABC's 2.6 rating was fourth, leaving The CW in fifth with a 0.7 rating.
 
Overall, though, it was CBS averaging an estimated 14.35 million viewers to go with an 8.7 rating/14 share. FOX was second with an 8.0/13 and an average of nearly 13.7 million viewers. ABC's 5.5/9 was good for third, beating the 4.3/7 for NBC. The CW's 1.1/2 trailed.
 
FOX started the night in first with an 11.1/18 for "American Idol," which drew 19.31 million viewers and a 6.5 demo rating for its results show. CBS was second with "Survivor: Heroes vs. Villains," which bounced back to a 7.2/12 without Olympics competition. ABC's "Grey's Anatomy" repeat was third, beating the 3.0/5 for NBC's "Community" and "Parks and Recreation." The CW's repeat of "The Vampire Diaries" had a 1.1/2 for fifth.
 
CBS moved into first overall at 9 p.m. with a 9.4/15 for "CSI: Crime Scene Investigation." ABC's new "Grey's Anatomy" was second overall with a 7.7/12 and still beat "CSI" in the key demo. NBC's "The Office," with the birth of Jim and Pam's baby, did a 5.2/8 and won the hour with a 4.7 demo rating. FOX's "Kitchen Nightmares" had a 4.8/8 for fourth. The CW's repeat of "Supernatural" retained most of its lead-in.
 
"The Mentalist" had a 9.1/16 for CBS in the 10 p.m. hour. ABC's "Private Practice" did a 5.0/9 and was third with a 2.5 demo rating. NBC's "The Marriage Ref" had a 4.6/8 in its time period premiere, winning the hour with a 3.2 demo rating. 
 
 
All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.