The premise is rather stale, the writing is uneven, and the supporting performances are mostly unremarkable. So why does FOX’s “New Girl” work so very well? Two words: Zooey Deschanel. Deschanel is the heart and soul of this new sitcom, which would be another mediocre fall pilot if not for her charming, hilarious presence.

Created by Elizabeth Meriweather, “New Girl” tells the story of Jess Day (Deschanel), an emotional, awkward, newly single woman who moves into an apartment with three bachelors (Max Greenfield, Jake Johnson and Damon Wayans). Sitcom-style gender clash ensues. Don’t expect any deep insights here, just a lot of fun.

Jess, as a character, is basically a combination of quirks from Deschanel’s past performances. This is not a bad thing—the character feels fresh and original, simultaneously bizarre and humane. The actors playing Jess’s roommates are primarily tasked with reacting to Deschanel’s oddities, which actually works reasonably well.

Wayans, whose character is referred to as “Coach,” is the standout among the male leads—his comedic timing is more natural than the others. This is unlucky, considering he’ll be gone by the second episode due to the renewal of his other show, “Happy Endings.” Lamorne Morris will be taking Wayans’s place as a new character named Winston Bishop. I’m already cringing at the tastelessness of coincidentally introducing a replacement black male lead in the second episode.

In the pilot, Greenfield and Johnson have trouble pulling off some of the broader jokes, but I have confidence that their performances will improve once their characters are given definition beyond “tool” and “wimp,” respectively. I am also reasonably optimistic that the writing will improve as the series progresses. The punch lines in the premiere feel overly calculated—likely a byproduct of the heavy script-tweaking that pilots endure. I think the writers can develop a more natural rhythm in subsequent episodes.

It would be great if the charm and unpredictability of Deschanel’s performance spread to the rest of “New Girl,” but, if not, the show succeeds well enough resting on her shoulders. Of course, there are a few downsides to relying solely on Deschanel. For one, the show has very little to offer viewers who are less enamored with her on-screen persona. Additionally, “New Girl” will be unable to compensate should Deschanel’s performance falter.

This strategy has worked well enough on other shows, though. Showtime’s “Weeds,” for instance, is often at the mercy of Mary-Louise Parker’s similarly hypnotic performance, and that’s enough to keep viewers tuned in every week. If audiences give “New Girl” a chance, I think Deschanel is relatable and appealing enough to attract a fairly widespread viewership. If the other elements of the show do improve, I could see “New Girl” becoming more of an ensemble piece reminiscent of “It’s Always Sunny in Philadelphia.”

This fall’s network television lineup is far from promising, especially when it comes to new series. Fortunately, the “New Girl” pilot brightens things up a bit. Though you won’t find anything revolutionary here, Deschanel’s committed performance makes the potentially great “New Girl” worth watching.

Grade: B+

Premieres Tuesday, September 20 at 8 pm on FOX