“On the Lot” failed to put up strong numbers despite airing after both “American Idol” and “So You Think You Can Dance” last week in its debut. Left on its own last night, the show performed even more poorly.

A two-hour “Lot” averaged a 1.3 adults 18-49 rating, according to Nielsen overnights, placing fifth in its first airing in its regular timeslot behind even Univision from 8 to 10 p.m.

The show fell from a 2.1 rating Thursday night, when it aired at 9:25 p.m. following the season premiere of “Dance,” last summer’s top-rated show on broadcast among 18-49s.

And it was down even more from a 3.9 for its premiere following “Idol” at 9 p.m. last Tuesday, though that came from a huge lead-in.

Fox had premiered “Lot” in the post-“Idol” position hoping to give the high-profile show some momentum. It’s executive produced by Steven Spielberg and Mark Burnett, and it gives amateur filmmakers a shot at their big break.

Of course, other original summer fare didn’t do so well last night on the other networks, either, and some of the blame can go to traditionally low Memorial Day viewing. But it’s not a good start to the summer for any of the networks, with ABC’s “Ex-Wives Club” and NBC’s now-canceled “Wedding Crashers” also averaging a 2.0 or worse.

In fact, last night reruns ruled. CBS finished first for the night among 18-49s with a 2.7 average rating and an 8 share, with ABC and NBC tied for second at 2.1/6, Univision fourth at 1.6/4, Fox fifth at 1.3/4 and CW sixth at 0.7/2.
 
ABC began the night in the lead with a 2.3 at 8 p.m. for “Wife Swap,” with CBS second with a 1.9 average for repeats of “How I Met Your Mother” and “The New Adventures of Old Christine.” Univision was third with a 1.6 for “La Fea Mas Bella,” NBC fourth with a 1.5 for “The Real Wedding Crashers,” Fox fifth with a 1.3 for an hour of “On the Lot” and CW sixth with a 0.8 for repeats of “Everybody Hates Chris” and “All of Us.”
 
At 9 p.m. CBS took the lead with a 3.2 average for repeats of “Two and a Half Men” and “The King of Queens,” followed by NBC with a 2.2 for the first hour of the “Miss Universe” pageant. That left ABC third with a 2.0 for “Ex-Wives Club,” Univision fourth with a 1.9 for “Destilando Amor,” Fox fifth with a 1.3 for another hour of “Lot” and CW sixth with a 0.7 for repeats of “Girlfriends” and “The Game.”
 
CBS led again at 10 p.m. with a 2.9 for a repeat of “CSI: Miami,” with NBC second with a 2.7 for its second half of “Universe,” ABC third with a 2.1 for “Supernanny” and Univision fourth with a 1.2 for “Cristina.”
 
Among households, CBS also led, finishing the night with a 5.4 average rating and a 9 share. ABC and NBC tied for second at 3.8/7, with Fox and Univision tied for fourth at 1.8/3 and CW sixth at 1.3/2.