There’s a pivotal scene in Adam Sandler’s 1998 comedy “The Wedding Singer” that offers a glimpse at his potential.

In it, Sandler’s pining musician character is having a drink with the fiance of a girl he is in love with, and realizes the guy might be cheating on her. He manipulates the man into admitting it, and pretends to play along as the lout begins to boast about his conquests. The camera focuses on Sandler’s half-smiling face as he tries to hold back his contempt.

There’s something dark and resonant about this scene.

Sandler is actually “acting.”

It’s one of the few moments from any of the comedian’s erratic film catalogue that suggest he could be capable of something more something beyond the inane yuck fests that he often walks through on his way to picking up a paycheck.

“Punch-Drunk Love” is like an entire movie of moments as good as that.

Edgy filmmaker Paul Thomas Anderson (“Magnolia”) has written a role specifically for Sandler, and it captures all the manic energy, the awkward shyness and sharp comic timing that the former “Saturday Night Live” standout can muster. It’s not that the star is bringing anything new to the table, it’s more he’s refining all his previous skills into one uber-Sandler role.

The actor plays Barry Egan, an isolated bachelor who owns a business that manufactures decorative toilet plungers. Barry is the only male among seven sisters who are always trying to fix their brother up on a date or just convince him to come out of his apartment once in a while.

Adam Sandler portrays a lonely bachelor in Punch-Drunk

To call him an introvert is an understatement. But his constant repression has its own consequences: Barry is prone to fits of destructive rage.

Lonely and confused, he dials up a phone sex service and has an intimate conversation with one of the gals. The company is really a front for a credit card scam run by a Utah furniture mogul (played by Anderson regular Philip Seymour Hoffman), who repeatedly tries to extort money from Barry.

Meanwhile, a British woman named Lena (Emily Watson) walks into Barry’s business one day. There’s a spark between them and they begin to date.

What follows is an ongoing battle between Barry and the porn kingpin’s thugs, while he and Lena attempt to hold a most unconventional courtship.

As much as Sandler blossoms in this tailor-made role, so too does writer-director Anderson. The brilliant filmmaker eschews the sprawling, improvised story lines of his previous efforts, such as “Boogie Nights,” to offer a tight, focused piece. (The movie doesn’t even run an hour and a half, compared with the three-hour snarl of “Magnolia.”)

“Punch-Drunk Love” is just as “weird” in its own way as “Magnolia.” It takes great pleasure in making the audience share Barry’s uncomfortability with his environment. Anderson achieves this by framing his star with atypical camera angles that exaggerate his surroundings, or having him disappear into darkness while next to a lit companion. (The hilarious opening sequence finds Barry seated at a desk in the corner of a warehouse from the way it’s shot he looks like an infant in an airplane hangar.)

Anderson, a master of using music as more than just soundtrack fodder, also chooses to break up scenes with title cards. Only these consist of kaleidoscopic sounds and colors instead of words.

This is a movie that exudes freshness at every turn. The plot never quite goes where one thinks it will (the final confrontation is a lesson in shattering audience expectations), and the narrative rarely loses momentum.

Compared to Anderson’s previous works of serious life-and-death magnitudes, “Punch-Drunk Love” could be criticized as a lightweight project for the director. But in its own modest way the picture is just as impressive. It doesn’t resolve with a grandiose finale or attempt to solve any social ills. It’s just a sweet love story between two outcasts.

It may seem small to some viewers, but the story looms large for Barry and Lena … and for Sandler.