On a night when the biggest and most potentially entertaining show in primetime looked to be the GOP debate over on Fox News Channel, it was pretty much falls and flats for the Big 4. The only rises of the night were NBC’s Food Fighters (0.9/3) and Dateline Thursday Night Mystery (1.1/4). The unscripted former was up 13% from last week among adults 18-49, the exact amount it was down from the week before, while the newsmag variation rose 10%.

Rising up was not the case on CBS on Thursday, but Big Brother (2.0/7) still was the top-rated show of the night. CBS actually was tops for the night overall with a 1.4/5 rating and viewership of 5.49 million. Even with its preliminary numbers of July 30, Big Brother dipped 5% from its final numbers among the demo. With 6.15 million tuning in, the veteran reality show was the second-most-watched show of the evening. The most watched was, like last week, a repeat of The Big Bang Theory (1.5/2). The Chuck Lorre-produced comedy drew an audience of 7.22 million, up a touch from July 30. The news was not so good for Under The Dome (0.8/2), with a 20% drop among the 18-49s from the week before and after two weeks of holding steady. That early result is a series low for UTD.

There was another series low in fast nationals with The Astronaut Wives Club (0.6/2) falling 25% last night. That’s another roller-coaster week for the ABC Space Race series, which was down over 30% two weeks ago and then up more than 30% last week. With that AWC decline as a lead-in, Mistresses (0.6/2) and Rookie Blue (0.6/2) both tumbled 14% to match series lows in early numbers.

Things stayed stable on The CW with Beauty And The Beast (0.2/1) and the finale of freshman Dates (0.2/1) both even with their July 30 shows.

Fox was all encores last night.