A few seasons ago Catherine Zeta-Jones won an Oscar for singing and dancing in “Chicago,” the movie. Some people thought it was a trick of editing.

Now, starring in Stephen Sondheim’s “A Little Night Music” on Broadway, Mrs. Michael Douglas cements her place as a stage star. It was no trick. She’s the real thing.

Last night, the culmination of Trevor Nunn’s extraordinary two-and-a-half hour revival was CZ-J’s stunning rendition of “Send in the Clowns.” It’s perhaps Sondheim’s best known and maybe best ever song, and Zeta-Jones performance was spot on. From the first line of the song — “Isn’t it rich/Aren’t we a pair?” — it was clear she had “it.” The audience in the tiny Walter Kerr Theater — which included Lauren Bacall, Hugh Jackman, Kathleen Turner, Nik Ashford and Valerie Simpson, Harvey Weinstein, and, of course, Michael Douglas —went wild.

(I like Hugh Jackman — he came upstairs to the mezzanine bar to get sodas for himself and wife Debra Lee at intermission — and waited in line in a narrow space to do it.)

And the numerous charms of “A Little Night Music” don’t all belong to Zeta-Jones. Angela Lansbury has been doing a victory lap on Broadway this year, winning a Tony last spring for “Blithe Spirit.” She returns to Sondheim (remember, she was the original, award-winning Mrs. Lovett from “Sweeney Todd”) triumphantly in “Night Music” as the curmudgeonly grandmother and, of course, steals the show. (It’s not so easy; her character is in wheelchair.) The show also features two tremendous male leads: Alexander Hanson, from the London production, and Aaron Lazar, plus the strongest cast of singers on Broadway in featured roles.

Over at Tavern on the Green later — at what may be the final theatre premiere party at the real Tavern thanks to the city and general greed — Zeta-Jones made an entrance suitable for her new station as Queen of Broadway. As befitting a Queen, her rude publicist just about knocked my kidney stone out of place elbowing me out of the way. But CZ-J was charming as ever, accepting kudos and flowers from husband Michael Douglas. Sondheim — without whom none of this is possible — made a brief appearance before scooting out of the spotlight.

As for Oscar-winning actor/producer Douglas, he did tell me some good news: his very good movie, “Solitary Man,” has been picked up by Overture Films and will be released on May 2nd, two weeks after “Wall Street 2.” It’s going to be a Michael Douglas spring. In the meantime, it’s a CZ-J winter as Douglas’s wife is signed to “Night Music” through July. This means no family Christmas outing to Bermuda — where Douglas’s mom is from and where he often vacations. “We’ll just stay here, and do a little skiing,” Michael told me. It doesn’t sound so bad!