MOVIE REVIEW : ‘Moonstruck’ Doesn’t Strike Twice : Norman Jewison’s romantic comedy ‘Only You’ would be hard enough for Cary Grant and Grace Kelly to carry, let alone Marisa Tomei and Robert Downey Jr.

“Only You” is mostly ersatz. An implausible romantic comedy that is flimsy even by the elastic standards of the genre, it counts on star power to compensate for a lack of originality, but it is not to be.

A fluffy knockoff of “Sleepless in Seattle” that makes that film’s charming plot seem as rigorously logical as a mathematical theorem, “Only You” owes so much to so many movies the word derivative isn’t quite strong enough.

While stars are defined by their ability to carry vehicles others couldn’t begin to lift, Marisa Tomei and Robert Downey Jr., certainly an engaging couple, are not up to the task here. Diane Drake’s script, directed by Norman Jewison, would strain the star power of Cary Grant and Grace Kelly, and Tomei and Downey, although they try their hardest, lack the heft to pull it off.

For a while, Tomei has the job all to herself. In a pair of brief prologues, Faith Corvatch is glimpsed as quite an impressionable young girl. First, at age 11, she and her bratty brother Larry manipulate a Ouija board to determine the name of her life’s soul mate. The answer: Damon Bradley.

Then, a couple of years later, a shady fortuneteller at a carnival utters the same name, along with a bit of pivotal advice: “The truth is, you make your own destiny. Don’t wait for it to come to you.”

Cut to 14 years later, when Faith is a perky teacher in a Catholic school, engaged to a fussy podiatrist named Dwayne who made the ultimate sacrifice at the moment of proposing: He turned off his beeper.

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But true to her name, Faith, a romantic who loves watching Ezio Pinza and Mary Martin sing “Some Enchanted Evening,” has not given up on her childhood fantasy of a soul mate named Damon Bradley. All this to the scorn of best friend and sister-in-law Kate (Bonnie Hunt), married to the grown-up but still drippy Larry (Fisher Stevens), who understandably thinks love is largely an imaginary notion.

All these issues might have remained theoretical except for a phone call from a long-lost friend of Dwayne’s, who talks only long enough to tell Faith he’s on his way to Venice and leave his name. Yes, it’s Damon Bradley.

Never mind that Faith is only 10 days away from her wedding. She has to find out if this Damon Bradley is her Damon Bradley, and, with a dubious but protective Kate in tow, immediately boards a plane for Italy to bring her quarry to earth.

Even if you buy this premise (a sizable if) and admire Marisa Tomei’s squeaky energy (somewhat easier to do), the twists “Only You” takes in Italy are predictable, preposterous or both as Faith pursues Damon through a host of feebly imagined difficulties.

Not even the appearance of a lively Robert Downey Jr. as a New Jersey shoe salesman who claims to be Damon Bradley clears things up. Increasingly wearing and bogus obstacles arise, and the question of whether this match is destiny or not gets dragged out to unnatural lengths.

What is dragged into the mix are Kate’s marital problems, as, not surprisingly, she is having Larry trouble. Trying to make her forget she even has a husband is the suave Giovanni (“Clear and Present Danger’s” Joaquim de Almedia), a standard-issue Italian who doesn’t miss an opportunity to say things like “the female body has always been the mystery, the essence of human life.”

All of “Only You’s” stars acquit themselves solidly, with Hunt making the strongest impression as the cynical Kate. But director Jewison, who covered similar territory more efficiently in “Moonstruck,” does not appear to have his heart in this version.

With loving shots of swank yachts, romantic restaurants and the kind of hotels the rich and famous frequent, “Only You” plays more like a pleasant travelogue than an involving film. While those desperate for even hollow romanticism will perhaps be satisfied, put up the slightest bit of resistance to this film and it falls apart in your hands.

* MPAA rating: PG, for some mild sensuality and language. Times guidelines: It features more romantic fantasy than sensuality.

‘Only You’

Marisa Tomei: Faith Robert Downey Jr.: Peter Bonnie Hunt: Kate Joaquim de Almedia: Giovanni Fisher Stevens: Larry A Fried/Woods Films and Yorktown Productions Ltd. production, released by TriStar Pictures. Director Norman Jewison. Producers Norman Jewison, Cary Woods, Robert N. Fried, Charles Mulvehill. Screenplay Diane Drake. Cinematographer Sven Nykvist. Editor Stephen Rivkin. Costumes Milena Canonero. Music Rachel Portman. Production design Luciana Arrighi. Art directors Stephano Ortolani, Maria Teresa Barbasso. Set decorators Ian Whittaker, Alessandra Querzola. Running time: 1 hour, 51 minutes.

* In general release throughout Southern California.