Fast National ratings for Friday, April 12, 2013.
 
"Happy Endings" and "Vegas" were among several shows taking big Friday drops, but ABC and CBS still split the night among young viewers, with CBS dominating overall.
 
For "Happy Endings," the drop continued the show's three week roller-coaster on Fridays, which have seen its key demo ratings go from 0.8 to 1.1 to 0.7, which sounds more impressive if you look at it in terms of percentages.
 
For "Vegas," a second week of subpar Friday numbers, this time against only repeat competition, probably augers poorly for its long-term future (not that it had much long-term future beforehand).
 
Oh and "Nikita" was up for The CW.
 
Among adults 18-49, ABC and CBS both averaged a 1.2 rating for Friday night, tops in the key demographic. NBC and FOX tied with a 0.8 key demo rating and The CW did a 0.3 key demo rating for Friday night.
 
Overall, though, CBS ruled with 8.18 million viewers and a 5.2 rating/9 share for Friday primetime, far ahead of the 3.0/5 and 4.32 million viewers for ABC. NBC averaged a 1.9/3 and 2.83 million viewers, topping FOX's 1.5/3 and 2.31 million viewers. The CW averaged a 0.6/1 and 955,000 viewers.
 
8 p.m. - "Undercover Boss" won the 8 p.m. hour with a low 7.3 million viewers and a 1.4 rating among adults 18-49 for CBS. NBC's "Fashion Star" actually ticked up with 2.91 million viewers and a 0.8 key demo rating for second. ABC's "Happy Endings" averaged 2.43 million viewers and a 0.7 key demo rating for two episodes, compared to the 2.08 million viewers and 0.7 key demo rating for FOX's repeat of "Kitchen Nightmares." The CW's "Nikita" averaged 1.32 million viewers and a 0.4 key demo rating.
 
9 p.m. - "Vegas" won the 9 p.m. hour overall for CBS with 7 million viewers, but finished third with a 0.8 rating among adults 18-49. ABC's "Shark Tank" repeat won the hour with a 1.3 key demo rating and finished second with a 5.11 million viewers. FOX's "Kitchen Nightmares" repeat averaged 2.54 million viewers and a 1.0 key demo rating, compared to NBC's "Grimm" repeat with 2.53 million viewers and a 0.7 key demo rating. The CW's encore of "Carrie Diaries" averaged 587,000 viewers and a 0.2 key demo rating.
 
10 p.m. - "Blue Bloods" was also down week-to-week and won the 10 p.m. hour for CBS with 10.245 million viewers, finishing second with a 1.3 rating among adults 18-49. ABC's "20/20" won the hour with a 1.5 key demo rating and finished second with 5.41 million viewers. NBC's "Rock Center" averaged 3.06 million viewers and a 0.8 key 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.