Ratings: Big Bang Bests American Idol, Person of Interest Hits Series High

The King of Nerds is poised to crown American Idol, based on at least the preliminary Nielsen ratings for this Thursday night.

The Big Bang Theory‘s very funny (and very green dress-y) 100th episode scored a 5.2 demo rating, squeaking past the first half hour of Idol’s Season 11 premiere, Part 2 (which netted a 5.1). Of course, Idol (as well as Leonard & Co.) could tick up some once the final numbers trickle in.

UPDATE: Adjusted data resulted in upticks for both Idol and Big Bang, but the geeks still came out on top; Idol‘s first half-hour climbed to a 5.2, while BBT inched up to a 5.3.

Michael Slezak’s American Idol Pittsburgh Audition Recap: Steel the One We Run To

Idol surged to a 6.1 rating from 8:30 to 9 (versus CBS’ Rob, which was down 12 percent to a 3.6), and trounced all comers in total audience with 17.7 million viewers (versus, say, Big Bang‘s 15.7 mil). Year-over-year, Idol was down more than 20 percent in both measures.

Week-to-week and in its first Idol face-off of the season, Big Bang Theory was down a tenth in the demo and just 2 percent in total viewers. The 8 o’clock show to be clobbered most by Idol was ABC’s Wipeout (5.8 mil/1.8, down almost 20 percent), while plucky Parks and Recreation (4.3 mil/2.0) actually inched up 5 percent.

Going hour-by-hour….

8 pm | Wipeout placed third behind Idol and the CBS comedies. 30 Rock (4.1 mil/1.6) dropped some 10 percent from its premiere, while Parks and Rec (as noted above) grew a bit. Vampire Diaries (2.72 mil/1.1) dipped 5 and 8 percent.

9 pm | Person of Interest (14.3 mil/3.3) dominated in total viewers and inched up a tenth in the demo to hit a series high. Grey’s Anatomy (9.3 mil/3.4) eked out the demo win, but was down double digits on both counts. Fox’s The Finder (6.8 mil/2.2) enjoyed a 29-percent demo boost from its Idol lead-in, yet still placed fourth in the category.

The Office was flat at 6 mil/2.9, while Up All Night (4.03 mil/1.9) slipped 5 percent. Secret Circle (1.66 mil/0.7) dropped 12 percent.

10 pm | The Mentalist dominated with 14 million total viewers and a 2.9 demo rating, up a few percentage points week-to-week. Private Practice (6.1 mil/2.1) was down 9 percent in the demo. NBC’s The Firm sagged another 19 and 10 percent, delivering just 3.4 mil and a 0.9.

What were you tuned into this Thursday?