Few visitors to Fenway Park even noticed when the undersized southpaw stepped into the batter’s box Monday afternoon for his first-ever showdown with the imposing Green Monster, 310 feet down the left-field line.

But after his first swing — a line drive up the middle that would have been a base hit in any major league park — the smattering of fans sitting in Boston’s bleachers knew exactly who was up at the plate: Rep. Sherrod Brown, a 51-year-old Democratic lawmaker from Ohio and a lifelong baseball fanatic.

“Now batting, Sherrod Brown,” the scoreboard announced in giant letters more than 450 feet from home plate.

“I’ve been to Fenway,” said a boyish Brown before stepping onto the diamond for his three chances to knock one out of the park. “I go to games when I am here. But now I get to bat at Fenway.”

Welcome to batting practice at Fenway Park, one of the most anticipated corporate-sponsored events at Democratic conventions, dating back to an outing at Chicago’s Wrigley Field in 1996.

“When you are out there, you think you are 15 years old again,” he added before his wife interjected: “And then you hurt your leg.”

The event is traditionally sponsored by a smattering of telecommunications firms and this year was no different except for the fact that News Corp. — the owner of the conservative Fox News Channel that Democrats love to hate — picked up the bill for the 900-person event.

But unlike the hundreds of other cocktail parties, receptions and late-night concerts sponsored this week by businesses and trade associations, News Corp.’s batting practice was one of the few events that allowed lawmakers and lobbyists to bring along their families for a little fun at the ballpark.

Each of the dozen Members of Congress who turned out at the park brought along a squad of sons and daughters, nieces and nephews, sons-in-law and daughters-in-law.

Rep. Mike McIntyre (D-N.C.) dressed his kids in bright blue baseball uniforms that read “Democrats” across the chest. Sen. Frank Lautenberg (D-N.J.) showed up with a team of grandchildren. And Rep. Marty Meehan (D-Mass.) sent his wife and toddlers to the stadium, since he was too tied up with convention planning to make it.

“I didn’t see one person I recognized,” said Ellen Meehan as she loaded her kids and an oversized stroller into her car. “It was a lot of kids.”

Of the lawmakers who made it to the park, few had the patience to wait through the hour-long line that stretched from the Green Monster in left field to home plate to face a maximum of three pitches.

Rep. Gary Ackerman (D-N.Y.), a lifelong Mets fan and one of the few lawmakers to step up to the plate, drew laughter from the hundreds in line behind him by making a plate appearance with his cane.

“I was going to scope the place out before deciding whether I was going to use my designated hitter,” he said, referring to his wife, Rita.

“As long as I don’t get hit in the face,” Rita responded.

Ackerman’s press secretary, Ross Wallenstein, accompanied his boss to Fenway. But he refused to bat.

“I’m a Yankee fan. I don’t want to get killed,” he said.

In addition to taking a few swings at the plate, the lobbyists, lawmakers and families were free to roam the stadium, try their hands at pitching in the bullpen, take a tour of the Red Sox locker room and eat free hot dogs, fries and sausages.

Red Sox greats Jim Rice, Jim Lonborg and Luis Tiant were on hand to sign autographs.

“It was a lot of fun,” said Eleanor DeMartino, an 80-year-old Red Sox fan who has been coming to games since the days when a seat in the bleachers cost 50 cents. “I’m a diehard Red Sox fan and a diehard Democrat.”

Critics complain, however, that the invitation-only event provided a splendid opportunity for News Corp. officials to schmooze with some of the Democrats who hold sway over the company’s fortunes on Capitol Hill.

Dozens of Democratic Congressional aides attended the outing, in addition to at least two men who would play central roles in a Kerry White House, David Castagnetti and Ivan Schlager.

“The contacts made at these type of convention events are very similar to those made through formal lobbying on Capitol Hill,” said Steven Weiss of the nonpartisan Center for Responsive Politics. “Certainly the goal of the hosts is the same — to curry favor with elected officials.”

But those who were lucky enough to be invited to the event maintained that it was all in good fun.

“It’s all family and friends. It’s just a good time,” said David Krone, a lobbyist for the cable industry who traded in his wingtips for a pair of tennis shoes.

Indeed, most of the few hundred people showed up with Red Sox jerseys on their backs, smiles on their faces and baseball gloves tucked under their arms.

“I’m just here to grab some hot dogs and beer,” said Tim Kraft, a Democrat who flew in from New Mexico for the convention. “The lobbyists are all going somewhere where they can drink something other than beer.”

Still, the News Corp. event clearly left impressions on lobbyists, lawmakers and kids of all ages. And there is little doubt that the Fenway event had major-league pull with Members of Congress: What better way for the owners of the anti-Democratic Fox News Channel to get in the same room with Sherrod Brown, one of the most liberal members of the Democratic party? (Never mind the fact that the room had 33,817 seats.)

After taking his three cuts at the plate, Brown — who plays center field in Roll Call’s annual Congressional baseball game between Republican and Democratic lawmakers — trotted to center field, where he practiced fielding deep fly balls off the outfield wall.

“He was throwing it off of all different points in the wall,” said his wife, Connie. Recounting what he learned, Brown concluded: “If you hit the seam, it bounces a lot further.”