Fast National ratings for January 5, 2012.
 
Facing reduced competition, ABC's "Grey's Anatomy" returned after a long hiatus with big numbers, carrying the network to a Thursday win in key measures.
 
Among adults 18-49, ABC averaged a 3.3 rating, beating CBS' 2.3 rating in the key demographic. FOX and The CW -- yes, The CW -- tied for third in the key demo with a 1.1 rating, while NBC averaged a 0.8 rating.
 
Overall, ABC averaged an estimated 9.46 million viewers and a 6.0 rating/9 share for Thursday night, edging out CBS' 5.8/9 and 9.34. FOX was far back in third with a 3.0/5 and 4.56 million viewers. The CW's 1.8/3 and 2.63 million viewers beat the 1.5/2 and 2.26 million viewers for NBC.
 
8 p.m. - CBS won the 8 p.m. hour with 10.15 million viewers and 3.0 key rating for repeats of "The Big Bang Theory" and "Rules of Engagement." ABC's "Wipeout" winter premiere averaged 8.54 million viewers and a 2.8 rating among adults 18-49 for second. FOX was third overall with 4.83 million viewers and fourth with a 1.2 key demo rating. The CW's "Vampire Diaries" repeat was fourth overall with 3.195 million viewers and third in the key demo with a 1.4 rating. NBC's repeats of "Community" and "Parks and Recreation" averaged 2.5 million viewers and a 0.8 key demo rating in fifth.
 
9 p.m. - "Grey's Anatomy" returned with 12.04 million viewers and a 4.5 rating among adults 18-49 to push ABC to a dominant 9 p.m. hour win. CBS' repeat of "Person of Interest" averaged 8.71 million viewers and a 1.9 key demo rating for second, far ahead of the 4.3 million viewers and 1.1 key demo rating for FOX's "Bones" repeat. NBC's "The Office" and "Whitney" repeats averaged 2.43 million viewers and a 1.0 key demo rating, edging out  the 2.06 million viewers and 0.8 key demo rating for The CW's "Secret Circle."
 
10 p.m. - CBS moved back into first overall in the 10 p.m. hour with 9.16 million viewers for a "Mentalist" repeat, which finished second with a 1.9 key demo rating. ABC's new "Private Practice" was second overall with 7.82 million viewers and won the hour with a 2.8 rating among adults 18-49. NBC's repeats of "The Office" and "Up All Night" averaged 1.85 million viewers and a 0.7 key demo rating for third.
 
All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.