Facing a field of mostly repeats, the first Thursday edition of Fox’s new quiz show “Are You Smarter Than a 5th Grader” continued to generate blockbuster ratings.

“Grader,” which aired for a full hour for the first time, earned a 9.4 rating among adults 18 to 49, according to Nielsen. That’s a 90 percent retention of its “American Idol” results show lead-in (10.5), a gain on Wednesday’s retention.

CBS was second with “Survivor” (5.0), growing 9 percent from last week, followed by repeats. ABC was third with repeats. NBC aired repeats of its 8 p.m. hour, followed by originals of “Scrubs” (3.3) and “30 Rock” (2.7) and a rerun of “The Black Donnellys” pilot. The CW also aired repeats.

(Editor: Romanelli)