Amy Schumer homers in her first major league at-bat. Trainwreck is funny and she is the movie’s title star. Just as importantly, she also gets the lone credit on the “written by” card.

Amy Townsend (Schumer) is not a loser. It’s her love life that’s a trainwreck. She’s a woman who men pursue. But most of her hookups are just one-night stands, a few of which are hilariously depicted in the film.

She’s a writer for a Maxim-like men’s magazine called S’Nuff. Her editor Dianna (Tilda Swinton) assigns her to write a profile of a sports medicine doctor, Aaron Conners (Bill Hader), whose patients include several big name pro jocks. Among them is LeBron James (played by, in a casting coup, LeBron James, who turns out to be an excellent performer).

Following her first visit with Aaron, he takes her to dinner. They spend the night together and begin a normal relationship, which is not Amy’s normal M.O. The inevitable bumps in the road occur leading to a happy resolution and solid laughter along the way. Along with the raunch, there’s some real sweetness.

The cast also includes Brie Larson as Amy’s sister Kim and Mike Birbiglia as Kim’s husband Tom. Colin Quinn is wonderful as Amy and Kim’s cantankerous, ailing father. Daniel Radcliffe and Marisa Tomei appear in an art house film that Amy attends with one of her less refined boyfriends (WWE wrestler John Cena). Ezra Miller and SNL vet Vanessa Bayer appear as Amy’s co-workers.

Director Judd Apatow has delivered raunchy romantic comedies with a heart before. He has nurtured talented actor/writers before. (See Seth Rogen.) Apatow’s a pro who knows where the good/bad taste line lies and dances all around both sides of it. Schumer’s script (which he acknowledges he tweaked) has some holes, but is fresh and funny.

Amy Schumer is riding high on a positive wave generated by a successful Comedy Central TV series and tons of good media publicity for Trainwreck. The horrible comments made earlier this year by internet trolls regarding her physical appearance—she’s not the traditionally glamorous babe seen in most rom-coms—have led to backlash in her favor.

Trainwreck would be a respectable effort if it came from a veteran. Coming from a rookie writer/actor, it’s damned impressive.