Jim Parsons Jim Parsons

The Big Bang Theory continued to dominate over American Idol head to head on Thursday, but it was a down night overall.

The hit sitcom scored 15.5 million viewers and a 5.0 rating in the adults 18-to-49 demo, easily trumping Idol's half-hour rating of 4.6. But Big Bang was down from its season-high 5.6 rating last week.

Check out our Idol recap

Armed with another two-hour Idol

episode, Fox won the night, with the show nabbing 16.5 million viewers and a 5.0 — dropping from a 5.8 last week for a one-hour episode.ABC's Grey's Anatomy-Private Practice crossover benefited only the latter, which rose to a 2.6 vs. last week's 2.2. Grey's, however, sunk to a season-low 3.1.But it was NBC who suffered the worst, with The Office plunging to a series low in the demo (2.2) and the rest of its comedy block failing to crack a 2.0 again.8 p.m.
The Big Bang Theory 15.5 million viewers (5.0 demo rating); Rob 10.9 million viewers (3.2)ABC: Wipeout 5.1 million (1.5)Fox: American Idol 16.5 million (5.0) [8-10 p.m.]NBC: 30 Rock 3.6 million (1.4); Parks & Recreation 3.5 million (1.7)CW: The Vampire Diaries 2.8 million (1.3)9 p.m.
CBS: Person of Interest 13.2 million (2.9)ABC: Grey's Anatomy 8.1 million (3.1)NBC: The Office 4.3 million (2.2); Up All Night 3.0 million (1.5)CW: The Secret Circle 1.75 million (0.7)10 p.m.
CBS: The Mentalist 13.6 million viewers (2.8)ABC: Private Practice 7.0 million (2.6)NBC: Grimm (R) 2.0 million (0.7)