The actress takes to the stage for a good cause and proves "she's got chops," says costar Rosie Perez

Jennifer Aniston had a one-night stand in Manhattan on Monday, impressing the crowd at the 6th Annual 24 Hour Plays on Broadway benefit, which featured six 10-minute plays conceived, written, rehearsed and performed all within one day.

In her play, Three Girls and Bob – her Broadway debut – Aniston played a single woman who attends an intimacy workshop with two friends (Rosie Perez and Lynn Whitfield) and then tries out its lessons on a hapless man (David Cross.) “It shouldn’t be this hard,” her character says of single life.

Costar Perez – who is on the board of the event’s beneficiary, Working Playground, which brings arts education to New York City classrooms – tells PEOPLE that Aniston lent star wattage to the event. “We had a real boost from Jennifer Aniston,” she said. “She was as sweet as pie. I really appreciated her coming because she raised the profile of tonight’s event and that is going to help so much. She didn’t have to do this. She didn’t have to take time out of her schedule.”

How did Aniston get involved? “The 24 Hour Plays people approached her and she said yes. But when she found out about Working Playground, she was over the moon. She said, ‘I’ll do all the press. I’ll do whatever you want.’ ”

Perez liked her acting, too: “She’s got chops. She said she had performed Off-Broadway. She’s really, really good.”

“She’s a total pro,” said Elizabeth Berkeley, who starred in another work performed Monday night. Other actors filling stages around Times Square included Anna Paquin, Gaby Hoffman, Kieran Culkin, Rachel Dratch, Julianna Margulies, Sam Rockwell, Liev Schreiber and Fisher Stevens.

“She was great,” Stevens said of Aniston. “She came in and did her job. She was just one of the regular people.”

Actors were asked to bring props and costumes to the initial cast meeting on Sunday at 10 p.m. “Aniston brought a chef’s jacket,” an insider tells PEOPLE.

The next morning at 8 she showed up by herself and worked hard the entire day, never mentioning her personal life or boyfriend Vince Vaughn – who himself participated in a 24 Hour Plays benefit in London on Oct. 8. “Why would she?” said her costar David Cross.

The 24 Hour Plays began at 10 p.m. the night before the show, when actors, writers and directors gathered at the theater to meet each other. The six writers worked through the night, crafting the 10-minute plays. The next morning, the directors chose and cast the plays before the actors returned to the theater and began rehearsing. At 8 p.m., after two hours of technical rehearsals, the performance began.

Judging by the reaction of the audience inside the American Airlines Theatre and the New York Post – which wrote in its Tuesday edition, “Jennifer Aniston made a hit debut on Broadway last night” – Aniston was a smash success.

At the Gran Centenario Tequila-sponsored afterparty at The W Hotel, Aniston sat at a banquette surrounded by friends, laughing and talking. “Call me,” she said to one male pal before she left.