“The only reason that we got it was because no one else wanted it, to be honest,” Mr. Abramcyk said. “The price was high for the shape, and the space was so unconventional, with the lack of windows and other types of things you’d normally want to showcase in a restaurant.”

The 29-year-old former hedge-fund manager and investor in the Hudson Street cocktail lounge Employees Only had been looking for a place to open his own bar; although he initially coveted an entirely different Greenwich Village address.

“I tried to get the Waverly Inn,” Mr. Abramcyk said, referring to the historic restaurant at 16 Bank Street, a space ultimately gobbled up by a group of well-heeled investors, including, most notably, Vanity Fair editor Graydon Carter.

When that deal didn’t work out, Mr. Abramcyk and his partner, Paul Sevigny, eventually settled on the abandoned Beatrice, a onetime speakeasy turned Italian eatery spanning roughly 2,000 square feet in the tight-quartered basement of a landmarked building that dated to the 1860’s.

“In hindsight, the Beatrice is definitely the place for us,” said Mr. Abramcyk, a lifelong New Yorker and self-professed antiques junkie who outfitted the ancient space with various “elements of Americana,” including old nautical mirrors and oil paintings.

Since it reopened in December 2006, the Beatrice has emerged as perhaps the hippest nighttime destination in all of Manhattan; an exclusive spot, though perhaps not quite as snooty or cost-prohibitive as the Waverly—and yet, arguably, twice as fashionable, at least among the young professional set.

“I wouldn’t say they are close to us in cool cred,” Mr. Abramcyk said of the rival West Village venue. “As far as the power-dinner crowd, I think the Waverly sets the bar. It’s the place that every other place is judged against. But nightlife places, that’s what we are; it’s a different thing. I would say there are maybe more cool people that come to our place because they can afford to. The Waverly Inn is very expensive.

“Obviously, it’s become one of the best places in the world of all time,” Mr. Abramcyk said of the Beatrice. “Not to sound like an arrogant fuck, but I believe in what we’re doing.”

“I think you have to be pretty impressed with what they have pulled off,” said Scott Solish, author of the blog Down By The Hipster, which chronicles Manhattan nightlife. “Beatrice is not a nightclub, they don’t pay for publicity, yet they have packed that place with a top downtown crowd for a pretty good stretch of time, including celebs, for whatever they are worth.”

The place’s popularity probably has a lot to do with Mr. Abramcyk’s partner, the veteran scenester Mr. Sevigny, a former professional skateboarder, a celebrated DJ, and a member of the downtown rock band A.R.E. Weapons—not to mention the older brother of the Oscar-nominated actress Chloë Sevigny. “Paul has just been around forever and knows a lot of people and, really, it’s a credit to him that the space is what it is today,” Mr. Abramcyk readily admitted.

But credit Mr. Abramcyk for locating such a stylish place to begin with. “I find all the spaces,” he said. “I do all the deals.”

THE DEALS ARE coming fast and furious these days for Mr. Abramcyk, whose career as an up-and-coming hospitality impresario seems to be blossoming as rapidly as patrons’ noses at his various gin joints. Just six months after reopening the Beatrice, Mr. Abramcyk also opened Smith & Mills, a tiny, 450-square-foot bar and restaurant on North Moore Street, located just a few blocks from his Tribeca apartment.

And he is far from finished. “In the last year, I’ve looked at about 150 different deals,” he said. “Right now, I’m looking at nine deals that I’m seriously involved in.”

These include a potential opportunity, first reported by New York magazine, to open another club in 6,800 square feet of basement space inside Soho’s historic Puck Building. (The Puck Building is owned by Kushner Companies; Jared Kushner, a principal, is publisher of The Observer.)

But that’s just Manhattan.

He and Mr. Sevigny recently signed on as “lifestyle consultants” on the forthcoming 330-room boutique hotel called the Chelsea in Atlantic City. “Matt’s got a real talent,” said Curtis Bashaw, the hotel’s developer. “He loves design. He loves architecture.”

He’s also in talks with the owners of the iconic Stratosphere hotel in Las Vegas about contributing to its pending redesign, and there are lingering rumors about another potential nightspot in Los Angeles.

“Paul and I have spoken about going out to L.A. and opening a business there,” Mr. Abramcyk said. “There’s a dearth of things like what we do out there. But it’s in such a nascent stage, there’s no meat on that bone.”

It sounds like an awful lot, especially for a guy who’s primary experience in hospitality came on the opposite side of the bar. “I’ve always loved going out in New York,” said Mr. Abramcyk, who traces his interest back to his days as a youngster partying at the old O Bar in midtown, located conveniently within stumbling distance of his parents’ home on East 58th Street. “Even at a young age, I would walk into places and quickly form opinions on the ambiance, the music, the décor, the personalities in there.”

The grandnephew of Nobel Prize-winning author Isaac Bashevis Singer, Mr. Abramcyk studied finance and English at New York University and later worked on Wall Street, with a brief stop along the way on the set of the NBC show Late Night With Conan O’Brien, which included an appearance as an extra on the recurring skit “Pubes”—an experience he is quick to reenact. “Let me just give you a taste of ‘Pubes,’” he said, laughing, during a recent interview at Smith & Mills.

The seeds of his nighttime entrepreneurship became firmly planted at Schiller’s Liquor Bar on the Lower East Side, where he spent a great deal of time after quitting his job in 2003 as a financial analyst. He and a friend, Akiva Elstein, also a Schiller’s employee, decided to open their own bar; they ultimately partnered, alongside several other investors, in opening Employees Only, and later, Smith & Mills.

“My great ambition in life is to affect as many people with my design ideas as possible, my aesthetic,” said Mr. Abramcyk, who is also engaged to be married this July to Nadine Ferber, proprietor of Mick Margo clothing shop in Greenwich Village. “Design is my whole thing,” he said. “It starts with the floors, up through the banquets, to the walls, the ceiling, the music, the people that are working in it—I consider all that design, although obviously the bones of the structure and build-out of the structure are my favorite part.

“The bones of the place have to speak to you,” he added, when asked what he looks for in a venue.

IT'S A QUICK learning curve, with a number of bumps along the way. “The rule in the business is you have to get rejected from 10 or 20 or 100 spaces,” he said. “Paul was looking for a bar for like seven years or something like that. So some people have to look at a thousand spaces, some people only have to look at a hundred; but either way, you have to look at a lot of spaces.”

Another rule he soon learned: You can’t choose your neighbors.

“I’m not going to lie to you—who’s living upstairs is key,” said Mr. Abramcyk, who recently made headlines when he took the unprecedented step of suing his upstairs neighbor, identified in court papers as Victoria Hillstron, over her alleged harassment of employees at Smith & Mills.

Lots of operators have issues with neighbors these days, but his is perhaps the most extreme example. Besides repeatedly calling police and various regulators, “falsely claiming violations,” according to the complaint, Ms. Hillstron allegedly smashed glasses, screamed at customers and once chased his partner, Mr. Elstein, into the bar’s basement. She has also bombarded news outlets with e-mails, making all sorts of allegations about the bar and Mr. Abramcyk in particular.

“There are loons everywhere in this city, but she happens to be No. 1,” said Mr. Solish of Down By The Hipster. “I have several e-mails she sent me ranting and raving about Smith & Mills that I would be happy to share.”

It’s an issue that the usually chatty Mr. Abramcyk likes to downplay as much as possible. “She feeds off this,” he said. “I don’t know what the solution is. I just want her to stop harassing us.”

Ms. Hillstron has yet to formally respond to the complaint, and Mr. Abramcyk’s attorney, David Jaroslawicz, is seeking a default judgement to have her evicted. A hearing is scheduled this week.

“But she left these lunatic messages on my machine, threatening me with the Bar Association, and that she’s going to see [Manhattan D.A. Robert] Morgenthau, and she’s going to see Indiana Jones, and everything else that she can think of,” the lawyer said. “And she tells people she’s Bruce Ratner’s sister. I mean, you can’t make this stuff up.”

“They made it up!” countered Ms. Hillstron, in a phone call to The Observer on Monday. “They flat-out made it up.

“They’re fruit loops,” she said, laughing. “But, darling, none of it happened! It isn’t true. Not Bruce’s sister. None of it. No broken bottles. No screaming, ‘Get out!’ I introduced them to all of our neighbors. We had a very lovely relationship. I was down there partying with them.”