RATINGS RAT RACE UPDATE: The CW Tops NBC From 8-10 PM In 18-49 For First Time

UPDATE, 2:05 PM: The CW’s The Vampire Diaries (1.3 in 18-49) held onto its fast national rating, and Reign (0.7) was down 0.2 due to an NFL pre-emption, but the network still averaged 1.0 in adults 18-49 for the night — beating NBC head-to-head from 8-10 PM on Thursday for the first time with regularly scheduled programming. NBC averaged 1.0 from 8-11 PM but 0.9 from 8-10 PM. Adjusted down were both Fox series — The X Factor (1.5, up .2 from last week) and Glee (1.4, flat) — while Big Bang went up a tenth. With the Latin Grammy Awards, Univision drew 4.6 million total viewers, 2.4 million of them adults 18-49, to finish No. 3 for the night behind CBS and ABC.

PREVIOUS, 10 AM: Is there a more lopsided time slot on TV than Thursdays 8 PM? CBS’ The Big Bang Theory (5.2 in adults 18-49, up a tenth from last week’s fast national) beat the other four shows in the half-hour combined by 11%. And that is with Fox and the CW getting a boost from NFL pre-emptions and before Big Bang gets its customary .1 Live+same day bump. CBS’ freshman comedies also got a week-to-week boost last night, 8% for The Millers (2.8) and 5% for The Crazy Ones (2.2), along with drama Elementary (1.8, up 13%), while Two And A Half Men (2.1) was flat.

But there was no bounce for NBC, with hourlong Parks & Recreation (1.0) down 9% to a series low and the rest of the shows all tying their series lows from last week: Sean Saves The World (0.9), The Michael J. Fox Show (0.9) and Parenthood (1.2). NBC’s average for the night slipped to a 1.0 in adults 18-49, the lowest ever for an in-season Thursday with regularly scheduled programming.

In the fast nationals, NBC is being edged by the CW (1.1). That probably won’t hold because of the CW’s NFL pre-emption, but there is a chance that the No.5 network could tie NBC in 18-49 and top it in 18-34. (For now, The Vampire Diaries is running even with last week, 1.3 in 18-49, while Reign is up two tenths, 0.9)

On ABC, Once Upon A Time In Wonderland tied its series low 0.9 rating yet again. Scandal (2.9) also was flat week to week to rank as the No.2 series on the night in 18-49 behind Big Bang. Grey’s Anatomy (2.5) was down a tenth. Fox aired an NFL game in New Orleans to big numbers, so its fast nationals will undergo serious reduction. The X Factor (1.6) and Glee (1.6) are currently up two tenths and a tenth, respectively, from the fast national last Thursday when Fox also carried a football game in one market. CBS easily won the night in adults 18-49 (2.6) and total viewers (11 million), fueled by Big Bang‘s 18.6 million viewers, the most since the season premiere.

Related stories

2012-2013 Season Network Rankings: CBS Sweeps In Final Numbers; ABC, CBS & Fox Tie In May Sweep

Full 2012-2013 TV Season Series Rankings

CBS Wins Season & Ties Sweep In Demo; ABC Tops Adults 18-49 In Season’s Final Week

Get more from Deadline.com: Follow us on Twitter, Facebook, Newsletter