Fast National ratings for Thursday, August 4, 2011.
 
Continuing the recent summer trend, CBS' "Big Brother" delivered Thursday's biggest audience overall and with young viewers, carrying the network past ABC's roster of originals.
 
Among adults 18-49, CBS averaged a 1.8 rating for the night, beating ABC's 1.5 rating in the key demographic. FOX's 1.2 rating and the 0.9 rating for NBC followed. The CW averaged a 0.3 rating for the night.
 
Overall, CBS averaged an estimated 6.32 million viewers and a 4.1 rating/7 share for the night. ABC was second was a 3.3/6 and 5.48 million viewers. FOX's 2.5/4 and 4.01 million viewers were good for a distant third, with NBC averaging a 1.8/3 and 2.62 million viewers. The CW averaged 996,000 and a 0.6/1.
 
8 p.m. - ABC started primetime in first with 6.57 million viewers and a 1.9 rating among adults 18-49 for "Wipeout." CBS' "The Big Bang Theory" and "Rules of Engagement" averaged 5.805 million viewers for second overall, coming in third in the key demo. FOX's "So You Think You Can Dance" results came in third with 5.16 million viewers and second with a 1.6 rating in the key demo. NBC's "Community" and "Parks and Recreation" averaged 2.05 million viewers, while The CW's "The Vampire Diaries" averaged 1.21 million.
 
9 p.m. - "Big Brother" pushed CBS into first in the 9 p.m. hour with 7.27 million viewers and a 2.7 rating among adults 18-49. ABC's "Expedition Impossible" finished second overall with 4.78 million viewers and a 1.4 demo rating. FOX was third with the 2.855 million viewers for "Glee," beating the 2.23 million viewers for NBC's "The Office" and "30 Rock." The CW's "Plain Jane" averaged 785,000 viewers.
 
10 p.m. - CBS stayed in first overall for the 10 p.m. hour with 5.89 million viewers for "The Mentalist." ABC's "Rookie Blue" was second overall with 5.09 million viewers and won the hour with 1.3 key demo rating.  NBC's "Law & Order: Special Victims Unit" was third with 3.585 million viewers.
 
All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.