Fast National ratings for Thursday, April 29, 2010.
 
While "Grey's Anatomy' posted a comfortable demo win in the 9 p.m. hour and "Private Practice" kept things close for ABC at 10 p.m., the numbers for "FlashForward" at 8 p.m. were so low that CBS had no trouble dominating that hour and controlling the night in most key measures.
 
For the most part, ratings were up for the first night of the crucial May Sweeps period, with the few exceptions including "FlashForward," The CW's "Supernatural" and FOX's "Fringe."
 
Among adults 18-49, CBS averaged a 3.4 rating, topping the 2.8 rating for ABC in the coveted demographic. NBC's 2.4 rating and the 2.3 rating for FOX followed. The CW's 1.3 rating trailed.
 
Overall, CBS averaged an estimated 13.595 million viewers to go with an 8.4 rating/14 share. ABC was a distant second with a 5.3/9, with FOX's 4.6/8 close behind. NBC was fourth with a 3.2/5 and The CW finished fifth with a 1.9/3.
 
"Survivor: Heroes vs. Villains" dominated the 8 p.m. hour with a 7.5/13 and a 4.0 demo rating. FOX's "Bones" was a solid second with a 5.8/10 and a 2.5 demo rating. ABC's "FlashForward" was third overall with a 3.5/6, a 1.5 demo rating and just under 5.14 million viewers. However, "FlashForward" was well behind NBC's "Community" and "Parks and Recreation" in the demographic. Actually, "FlashForward" was dead last in the demo, as The CW's "Vampire Diaries" did a 2.1/4 overall, with nearly 3.4 million viewers and a 1.6 demo rating.
 
In the 9 p.m. hour, "CSI: Crime Scene Investigation" won overall for CBS with an 8.5/14, but its 3.0 demo rating was only good for third. ABC's "Grey's Anatomy" had a 7.0/11 overall and a 3.8 demo. NBC's "The Office" and "30 Rock" averaged a 3.8/6 and a 3.3 demo rating. FOX's "Fringe" was fourth with a 3.4/5 and a 2.0 demo rating, but very slightly down from last week. The CW's "Supernatural" was in line with its season averages (but down a bit from last week) in fifth.
 
CBS' "The Mentalist" won 10 p.m. with a 9.2/16 overall and a 3.2 demo rating. CBS' "Private Practice" was second with a 5.4/9 and a 3.0 demo. Facing new competition on both sides, NBC's "The Marriage Ref" limped to a  2.8/5 and a 2.0 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.