Fast National ratings for Thursday, May 13, 2010.
 
ABC won two-thirds of Thursday night in the key demographic, but thanks to another dismal performance by "FlashForward," CBS was still able to eke out a win for the night in the demo, while dominating overall.
 
Among adults 18-49, CBS averaged a 3.3 rating, beating the 2.8 rating for ABC in the all-important age group. FOX's 2.4 rating and the 2.2 rating for NBC followed. The CW's solid 1.5 rating was fifth.
 
Overall, CBS had a larger margin of victory, averaging an estimated 13.61 million viewers to go with an 8.3 rating/14 share. ABC's 5.6/9 was second, with FOX taking third with a 4.6/8. NBC's 2.9/5 held off the 2.0/3 for The CW.
 
CBS won the 8 p.m. hour with a 7.6/13 and a 3.9 demo rating for "Survivor: Heroes vs. Villains." FOX's "Bones" was a sturdy second with a 5.6/10, slightly up from last week. ABC's "FlashForward" was third overall with a 3.2/6, but dead last in the demo with a 1.3 rating. NBC's "Community" and "Parks and Recreation" had a 2.7/5 for the hour, as the addition of Rob Lowe to the "P&R" cast produced a statistically irrelevant bump in the 18-49 demo and a statistically irrelevant drop in total viewers. The CW's "The Vampire Diaries" closed its first season with a 2.1/4 and a 1.7 demo rating.
 
"CSI: Crime Scene Investigation" kept CBS in first overall at 9 p.m. with an 8.1/13, though CBS was third in the demo. ABC's "Grey's Anatomy" was second overall with a 7.2/12, but first in the demo with a 3.8 rating. FOX's had a 3.7/6 and a 2.3 demo rating. NBC finished fourth overall with a 3.5/6 for "The Office" and "30 Rock," but came in second in the demo. The CW's "Supernatural" got a small bump for its season finale.
 
"The Mentalist" completed CBS' overall sweep with a 9.1/16. ABC's "Private Practice" got a finale bump and did a 6.3/11 overall and a 3.2 demo rating, taking first for the hour. NBC's "The Marriage Ref" was substantially down from last week in a distant 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.