NEW YORK — There's nothing like starting a play in mid-volcanic eruption.

Which is what Neil LaBute does in "reasons to be pretty," where a verbal slugfest is in progress between a pair of battling lovers, Greg (Thomas Sadoski) and Steph (Alison Pill). Prepare to be bruised — and fascinated.

LaBute is in contentious-relationship territory here, and nobody quite captures guy mind-set as well as he does, particularly when attitude, misguided or not, is at the heart of the argument. The playwright has a special knack of making the fumblings and foibles of the male sex seem extraordinarily real.

But then LaBute has been given a galvanizing production (courtesy of MCC Theater), directed with assurance by Terry Kinney and populated with a superb quartet of actors that also includes Pablo Schreiber and Piper Perabo.

Greg, stuck in an anonymous dead-end, blue-collar job, is the centerpiece of the action. He's a boy-man whose offhand comment about Steph's physical attributes sets off a disturbance that leads to their breakup. Sadoski, in one of those amazing performances that exudes a painful truthfulness, portrays a genial guy who learns the hard way that he is in over his head when it comes to women.

Despite his lapses, Greg is sensitive — he seems to have an interest in 19th-century American literature.

He's definitely not like Kent, his opportunistic friend, who is cheating on his wife, Carly, with a younger woman. Portrayed by Schreiber with just the right amount of shallow, narcissistic bravado, Kent is a kind of raunchy Peter Pan, a man refusing to grow up, no matter what the consequences.

His main concern seems to be propelling the company baseball team to a trophy and not working on his marital situation with his pregnant helpmate (Perabo).

It's inevitable that the two men will come to blows, a brute-force confrontation staged with surprising realism.

Pill plays a woman deeply hurt by her boyfriend's assessment of her looks, a hurt that takes Greg a long time to understand. It's a lovely portrait of a person desperately in love but unable to get past what she considers an unforgivable transgression.

LaBute says "reasons to be pretty," which is having its world premiere at off-Broadway's Lucille Lortel Theatre, is the third part of an impressive trilogy. All deal with perceptions of physicality.

In 2001, New York saw "The Shape of Things," in which a woman, with ulterior motives, remakes her nebbish boyfriend into something he isn't. And three years later, in "Fat Pig," the playwright gave us one man's infatuation with a full-figured woman — much to the consternation of the man's good friends.

This final chapter is the best of a lot. It's LaBute's most adult story — or at least, his most touching tale — primarily because its struggling hero, if you can call him that, really does want to grow up.