Hamming it up in A Funny Thing Happened on the Way to the Forum at Matunuck’s Theatre by the Sea are, from left, Michelle Petrucci, Barrington’s Rachel Brown, Rachel Lomax, Zachary James as the vain captain of the guard, Kendal Hartse and Lauren Sprance .

Mark Turek Mark Turek

A very funny thing is happening at Matunuck’s Theatre by the Sea. After being closed for almost four years, the theater has bounced back with a dynamite production of Stephen Sondheim’s A Funny Thing Happened on the Way to the Forum.

It’s a riotous romp, a delicious bit of burlesque that bodes well for the future of the place. If this Forum is any indication of things to come, then Matunuck is in good hands.

The amazing thing is this tight show, cast for the most part in New York, was put together in just a couple of weeks with direction from Aimee Turner, the theater’s producing artistic director. Indeed, it was just over six weeks ago that new owner Bill Hanney bought the South County landmark.

And it hasn’t taken long for crowds to find their way back. The theater has already extended the show’s run by a week because the response has been so strong. It now closes Sept. 2.

At Friday’s $75-a-seat opening, people showed up early in a cold rain and huddled on the porch where they sipped champagne. Afterward they made their way along the garden walkway for a reception at the adjacent Seahorse Grill.

Former owners Renny Serre and Laura Harris were on hand, as well as Tommy Brent, who produced shows in Matunuck for more than two decades. Brent hadn’t stepped foot on the property in 17 years, said Hanney.

But that was only icing on the cake for what turned out to be a smashing night of theater. The only weak spot was the band, which sounded ragged at times and out of tune. But the singing was solid and the stage antics often side-splitting.

Outstanding performances came from portly Jean-Pierre Ferragamo as Pseudolus, the scheming slave who will do anything to win his freedom; rubber-faced Christopher Swan as the high-strung servant Hysterium, and lanky Zachary James as the vain captain of the guard, Miles Gloriosus.

The trio played up the gags, predictable as they often were, and it worked.

Actually, Forum contains just about every comic trick in the book, from drag roles to the pandemonium caused by mistaken identities.

Pseudolus strikes a deal with his young master Hero, who has fallen for a courtesan who lives in the brothel next door: Fix Hero up with Philia and he’ll get his freedom, a state that is speculated upon in the catchy song “Free.”

But there is just one problem. Philia, who is new to the courtesan game and still a virgin, has been promised to the conceited army captain Miles Gloriosus, who is on his way to fetch her. That means Pseudolus must act fast.

As things develop, Pseudolus hatches one crazy plan after another. At first he tries to buy Philia from brothel owner Marcus Lycus, before learning that she has already been spoken for. He tells Lycus he’s looking for a wife and Lycus parades out his women, in a long, drawn out routine that wore a little thin. Act I spends a lot of time on the set up.

Then Pseudolus decides to drug Philia by putting a sleeping potion in a glass of wine and passing her off for dead. That way, Miles will go on his way and leave Philia to marry Hero. But Philia’s religion prevents her from drinking alcohol, and the plan fizzles.

Meanwhile, Hero’s father Senex, who has been off in the country visiting his sickly mother-in-law, returns to Rome unexpectedly, and Philia, who is staying in his house, mistakes him for Miles.

“Take me,” she says, as Senex shows up at the door.

This leads to another long but humorous routine in which the aged Senex, who thinks Philia is the new maid, prepares to seduce his son’s young girlfriend. Senex and Pseudolos then sing “Everybody Ought to Have a Maid,” which adds another character each time a new verse rolls around, proving there is nothing terribly subtle about this show. It’s out and out vaudeville.

The cast is almost all new to Matunuck, except for Bob Del Pazzo, the horny Senex. Del Pazzo, a comic ace, made his professional debut in Matunuck 37 years ago as Sancho in Man of La Mancha, and he spent the next six summers here.

Most of the actors were on the youngish side, though, with people like William Nash Broyles, the musical’s fresh-faced Hero; Evy Ortiz as a charming Philia, and Barrington college student Rachel Brown as one of the courtesans.

But Ferragamo, a very physical Pseudolus with a twinkle in his eye; Swan, a master of timing as Hysterium, and James, a booming baritone with a lot of opera experience, stood out.

There was something wonderfully mischievous about Ferragamo, something infectious. And Swan was priceless in drag, as he dressed as Philia and sang the reprise of the self-flattering song “Lovely.”

In lesser roles, Harold Ashton was a hoot as Erronius, the ancient neighbor whose children were kidnapped by pirates. Erronius is told his house is haunted and that he must circle the seven hills of Rome seven times to rid the dwelling of spirits. Every now and then he would wander across the stage with his walking stick, as he completed yet another lap.

“That’s two,” he’d say.

And Bruce Warren was an excellent Marcus Lycus, the brothel owner.

Since the show was put together so hastily, the producers went with a rented set and costumes, which were perfectly fine. Three colorful Roman villas — the brothel and the homes of Senex and Erronius — are nestled together on stage.

Most people don’t need an excuse to head to South County in the summer. But if you need one, Matunuck is it. It’s got the best show in town.

A Funny Thing Happened on the Way to the Forum runs through Sept. 2 at Theatre by the Sea, 364 Cards Pond Rd., Matunuck. Tickets are $39-$49. Call (401) 782-8587 or log on to www.theatrebythesea.com.