Three of the big four broadcast networks finished in a tight bunch atop the ratings for Wednesday prime time, based on Nielsen overnights for the key 18-49 demo.

TVbytheNumbers.com reports that CBS, ABC and Fox all finished within a tenth of a point of each other, with NBC a distant fourth. NBC also finished fourth in total viewers, with CBS forging a lead over the pack in that metric.

The bad news for NBC was spread throughout all three hours of prime time. "Revolution" got the ball rolling at 8 p.m. by sinking to a new series low, a 1.5 average in viewers 18-49, down one-tenth of a point from last week. Next up was "Law & Order: SVU," which fell four-tenths from a week ago to a 1.6. At 10 p.m., "Ironside" finished a distant third among three networks with a 1.1 average, down two-tenths.

ABC had the top show of the night among the broadcast nets in "Modern Family," even though the show fell four-tenths of a point from the previous week to record a 3.8 average in 18-49. The show’s decline from a week ago was part of an across-the-board dropoff for ABC. Suffering the hardest hit was "Super Fun Night," which plummeted seven-tenths to a 2.5 average. "The Middle" slipped one-tenth to a 2.2, "Back in the Game" was off two-tenths to a 1.7, and "Nashville" also shed two-tenths to settle for a 1.7.

CBS matched ABC’s overall 2.3 prime-time average in the 18-49 demo to tie for the lead, but also saw its entire prime-time lineup lose ground. "Survivor" was down three-tenths from a week ago with a 2.4 average, "Criminal Minds" dipped one-tenth to a 2.6, and "CSI" equaled its series low with a 1.9, falling two-tenths.

Fox finished right on the heels of CBS and ABC, with its two-hour "X Factor" delivering a 2.2 average in adults 18-49, down two-tenths from a week earlier.

For prime time overall, CBS and ABC averaged 2.3 ratings in the 18-49 demo, followed by Fox (2.2 average), NBC (1.4) and Univision (1.2). CBS came out on top in total viewers with 9.7 million, followed by ABC (7.2 million), Fox (7.1 million), NBC (5.6 million) and Univision (3.1 million).