None of the big four broadcast networks came away unscathed Wednesday night as prime time produced a ratings bloodbath, based on Nielsen overnights for the key 18-49 demo.

TVbytheNumbers.com reports that two NBC dramas — "Revolution" and "Chicago P.D." — set new series lows, as did Fox’s "American Idol" and ABC’s "Mixology," while CBS’s "Criminal Minds" matched its all-time low in the key demo. For good measure, CBS’s "Survivor" equaled its season low.

Third-place NBC may have been the hardest hit by the carnage, as ABC’s fourth-place finish came with a lineup of mostly repeats. NBC’s "Revolution" slipped 8% from a week ago to a series-low 1.2 average in viewers 18-49, while "Chicago P.D." lost 13% and settled for a series-low 1.4.

NBC’s "Law & Order: SVU" was also down, dipping 6% from last week to a 1.5 average in 18-49.

Fox and CBS tied at the top of the 18-49 rankings, both with 2.2 averages for prime time overall. CBS’s "Survivor" was the top show of the night, even with its season-low 2.4 average, and it beat Fox’s two-hour "Idol" with its series-low 2.2 average.

CBS’s "Criminal Minds" equaled its series low with a 2.2 average in adults 18-49, dipping 4% from a week ago, while "CSI" held steady with a 2.0.

"Mixology" was ABC’s only fresh program of the night, and it fell 20% from a week ago to a series-low 1.2 average in 18-49.

When the dust settled over prime time overall, Fox and CBS led the battered group to the finish line in viewers 18-49, both with 2.2 averages, followed by NBC (1.4 average), ABC (1.1) and Univision (1.0). CBS inched ahead in total viewers, averaging 10.0 million to lead Fox (9.6 million), NBC (5.2 million), ABC (3.8 million) and Univision (2.6 million).