Actor Jim Parsons from ''The Big Bang Theory'' holds up his Emmy award for outstanding lead actor in a comedy series backstage at the 63rd Primetime Emmy Awards in Los Angeles
Actor Jim Parsons from ''The Big Bang Theory'' holds up his Emmy award for outstanding lead actor in a comedy series backstage at the 63rd Primetime Emmy Awards in Los Angeles September 18, 2011. Reuters

The Big Bang Theory was the top-rated show Thursday night as Fox won overall on the strength of X Factor, according to preliminary numbers. CBS's new How to Be a Gentleman lost much of its Big Bang lead-in, but held on to a decent rating.

The Big Bang Theory, airing on CBS at 8 p.m., took a 4.8 rating/15 share in the adults 18-49 demographic, snaring 14.5 million total viewers, which made it the most-watched program of the evening. The series premiere of How to Be a Gentleman at 8:30 took a 2.7/8 in the demographic and 8.9 million total viewers. It was down 33 percent from the premiere last season of the now-canceled $#*! My Dad Says.

Person of Interest was next at 9, slipping 13 percent from its series premiere last week with a 2.7/7 and 12.4 million total viewers. The network closed the evening at 10 with The Mentalist, which slipped 11 percent with a 2.5/7 and 12.7 million total viewers.

Fox's The X Factor from 8-10 drew the night's second-highest numbers with a 3.8/10 and 11.9 million total viewers, which gave the network the highest overall average of the night.

ABC experienced a night of downturns, starting with Charlie's Angels at 8, which dropped 29 percent to a 1.5/4 and 7.1 million total viewers. Grey's Anatomy the following hour dipped 15 percent for a 3.5/9 and 10 million total viewers. The night ended for the network with the Private Practice season premiere at 10, which slipped 15 percent versus last fall's premiere to give the show its lowest premiere ever with a 2.8/8 and 7.8 million total viewers.

At NBC, Community at 8 received a 1.8/5 in the demographic and 4 million total viewers, while Parks & Recreation at 8:30 took a 2.1/6 and 4.3 million total viewers. The Office at 9 was down 13 percent from its season premiere last week with a 3.4/9 and 6.6 million total viewers. The new comedy Whitney, meanwhile, fell 24 percent from last week's premiere, taking a 2.5/6 and 5.3 million total viewers. Prime Suspect at 10 was down 17 percent, getting a 1.5/4 and 5.5 million total viewers.