Fast National ratings for Thursday, August 25, 2011.
 
A special double-eviction episode of "Big Brother" (and NFL preseason preemptions in certain markets) led CBS to yet another comfortable win on Thursday night. [Other networks were also impacted by NFL preseason, pretty much rending Thursday's Fast Nationals a mess. This will end soon.]
 
Among adults 18-49, CBS averaged a 2.2 rating for the night, topping ABC's 1.5 rating in the key demographic. FOX averaged a 1.1 rating, followed by NBC's 0.9 rating and the 0.4 rating for The CW.
 
Overall, CBS averaged an estimated 7.2 million viewers for the night along with a 4.5 rating/8 share. ABC was second with a 3.4/6 and 5.695 million viewers, a good way ahead of the 2.7/5 and 4.25 million viewers for FOX. NBC averaged 2.91 million viewers and a 2.0/3 for the night, while The CW averaged 0.6/1 and 1.03 million viewers for the night.
 
8 p.m. - CBS' NFL-boosted "The Big Bang Theory" and "Rules of Engagement" won the 8 p.m. hour with 7.04 million viewers and a 2.0 rating among adults 18-49. ABC was a close second with 6.75 million viewers and a 1.9 key demo rating for "Wipeout." FOX's "Bones" averaged 3.96 million viewers, beating the 2.66 million viewers for NBC's "Community" and "Parks and Recreation." On The CW, "The Vampire Diaries" averaged 1.27 million viewers.
 
9 p.m. - "Big Brother" (and some quantity of football) averaged 8.48 million viewers and a 3.2 rating among adults 18-49 for CBS in the 9 p.m. hour. ABC's "Expedition Impossible" finale was second with 5.2 million viewers and a 1.5 rating in the key demo. FOX's "Bones" averaged 4.53 million viewers and beat the 2.85 million for NBC's "The Office" and "30 Rock." The CW's "Plain Jane" drew 789,000 viewers.
 
10 p.m. - CBS closed primetime in first overall with 6.1 million viewers for "The Mentalist," which also tied for the hourly win with a 1.3 rating in the key demo. ABC's "Rookie Blue" was second overall with 5.14 million viewers and also tied for the demo win. NBC was third with the 3.22 million viewers for "Law & Order: Special Victims Unit."
 
All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change, particularly in the case of live events.