LOS ANGELES — Thursday night saw the return of TV veterans Robin Williams and Michael J. Fox, with Williams easily getting the bigger audience.

Williams was back to his wacky antics for the debut of CBS’ “The Crazy Ones,” and his shtick appears to still have a certain pull with viewers, despite lukewarm reviews.

With a big boost from “The Big Bang Theory,” the comedy series that stars Williams as a copywriter at an ad firm run by his daughter, played by Sarah Michelle Gellar, drew 15.6 million viewers, according to early numbers from Nielsen.

“Crazy Ones” posted a rating of 4.0 in the key 18-49 demographic, in which a ratings point equals roughly 1.3 million viewers.

“The Big Bang Theory,” for which Jim Parsons just won an acting Emmy, had back-to-back new episodes leading into “The Crazy Ones.” The first drew 18.3 million viewers and a demo rating of 5.3, up 6 percent from last year’s premiere.

The second “Big Bang” episode brought in an audience of 19.5 million and an 18-49 rating of 5.8, for an increase of 16 percent compared with last year, making it easily the highest rated show of the night.

After Williams’ show was “Two and a Half Men.” The Ashton Kutcher-anchored series fell 17 percent from last year’s premiere to a 2.9, and “Elementary” fell 32 percent to a 2.1.

In all, CBS was the winning network for the night with more than 14.2 million viewers and a 3.7 in 18-49.

NBC aired back-to-back episodes of “The Michael J. Fox Show.” The combined audience for the two didn’t fare nearly as well as Williams’ series. The two episodes had 7.28 million viewers and a rating of 2.1 in 18-49, making it one of the lowest rated comedy premieres of the season. However, the show maintained its rating through the full hour and grew its audience by 2 percent.

“Michael J. Fox” also had a considerably weaker lead-in from “Parks & Recreation,” which drew a 1.3 rating, down 24 percent from last year’s season opener. Family tearjerker “Parenthood” was down 16 percent from last year.

Next week, “Sean Saves the World” will air at 9 p.m. ET and “Michael J. Fox” will follow at 9:30.

ABC followed a rerun of “Marvel’s Agents of S.H.I.E.L.D.” with a two-hour season premiere of “Grey’s Anatomy,” which drew 9.26 million viewers and a rating of 3.4., down 23 percent from last year’s one-hour debut.

Distributed by MCT Information Services