Fast National ratings for Wednesday, March 19, 2014.

With "American Idol" lagging behind "Survivor" in the 8 p.m. hour and only edging "Criminal Minds" among young viewers in the 9 p.m. hour, CBS and FOX had a tight race for Wednesday supremacy. As of now, the two networks tied in the key demographic and CBS holds a slim advantage overall, though anything could change.

Among other notables, "Mixology" took a solid drop without a new "Modern Family" as lead-in, while NBC's various dramas were also down a hair.

The CW had the night's best news, as "The 100" premiered above its "Arrow" lead-in, giving the network its biggest midseason hit since the 2010 premiere of "Life Unexpected." "The 100" was The CW's most watched show in its time period since September 2010.

On to the numbers...

Among adults 18-49, FOX and CBS both averaged a 2.2 rating for Wednesday night, tops in the key demographic. [CBS had a slim advantage in the two primetime hours the networks share.] NBC was third with a 1.4 key demo rating, followed by ABC's 1.1 key demo rating and The CW's 0.8 key demo rating.

Overall, though, CBS had first alone with 9.91 million viewers and a 6.2 rating/10 share for Wednesday, nipping FOX's 9.66 million viewers and 6.0/10 for the night. There was a sizable drop to NBC's 5.2 million viewers and 3.5/6, which topped ABC's 2.5/4 and 3.835 million viewers. The CW averaged 2.51 million viewers and a 1.6 key demo rating.

8 p.m. - "Survivor: Cagayan" led the 8 p.m. hour with 9.58 million viewers and a 2.4 rating among adults 18-49, just ahead of the 9.49 million viewers and 2.1 key demo rating for "American Idol" on FOX. [It's the second straight week that "Survivor" has beaten "Idol" in both measures in Fast Nationals, though "Survivor" lost its overall lead in Finals last week.] ABC's repeats of "The Middle" and "Suburgatory" averaged 4.58 million viewers and a 1.2 key demo rating, compared to the 4.3 million viewers and 1.2 key demo rating for NBC's "Revolution." The CW's "Arrow" averaged 2.36 million viewers and a 0.8 key demo rating.

9 p.m. - "Criminal Minds" won the 9 p.m. hour overall with 10.055 million viewers, finishing second with a 2.2 rating among adults 18-49. "American Idol" rose to 9.83 million viewers and an hour-winning 2.3 key demo rating. NBC's "Law & Order: Special Victims Unit" averaged 5.645 million viewers and a 1.5 key demo rating, compared to ABC's repeat of "Modern Family" (5.36 million viewers and a 1.7 key demo) and a new "Mixology" (3.6 million and a 1.2 key demo). The CW's "The 100" drew 2.66 million viewers and a 0.9 key demo rating for its premiere.

10 p.m. - "CSI: Crime Scene Investigation" won the 10 p.m. hour easily with 10.09 million viewers and a 2.0 rating among adults 18-49. NBC's "Chicago PD" had a weak night with 5.67 million viewers and a 1.4 key demo rating, failing to get a bump from ABC's "Nashville" doing 2.45 million viewers and a 0.6 key demo rating for a repeat.

All ratings information comes from preliminary Fast National Nielsen data, which includes live and same-day DVR viewing. All numbers are subject to change.