Preparing to exit: Jim Norton and Kate Baldwin in a scene from "Finian's Rainbow"

When the Irish-themed musical "Finian’s Rainbow" opened on Broadway last night, one thing was certain from the outset: It was a monster hit.

Featuring a flawless cast of Broadway talent bringing their A-game, the show has it all — one of the most-beguiling musicals ever written and a cast know who knows how to mine its riches for that pot of gold.

This is music from the golden age of the American musical, after all, a heady brew of misty-eyed Irish ballads and Harlem-era jazz numbers that’s guaranteed to tug your heartstrings and get your feet tapping.

On opening night, in an audience full of celebrities, each song proved so transporting that people were applauding before song's end.

If you haven’t seen it, it would be easy to assume that "Finian’s Rainbow" is another nearlethal dose of offensive Irish hokum. But did you know that the show tackles what happens to ordinary people during a credit crisis (a plot that's oh-so relevant) or that beneath its big, warm-hearted exterior, "Finian’s Rainbow" is still packing a social punch that’s as potent as when it the show was first written 60 years ago?

The story begins when old man Finian McLonergan (played by Irish actor Jim Norton, who looks born to play the role) moves to the Deep South from old Ireland with his daughter Sharon (played by the electrifying singer Kate Baldwin). Finian has a harebrained plan to bury a pot of gold (stolen from the leprechaun’s) near Fort Knox in the mistaken belief that it will grow even more. But outraged by the theft, a young leprechaun named Og has followed father and daughter all the way from home, desperate to recover his stolen treasure before the loss of it turns him permanently human.

As plots go, it’s completely ridiculous, but it allows the show to tackle an issue that’s all too real: what happens to a society when the bigoted and corrupt leader Senator Billboard Rawkins throws his weight around, thereby allowing reality to show up in all its ugliness, until wishes are made over the magical crock of gold restoring justice.

This being a Broadway musical, all roads lead to the happiest of happy endings.

At its core, "Finian’s Rainbow" tackles the way that racial intolerance blights the lives of everyone it touches. That’s as dangerous a subject for a musical as can be, but the show takes it on with wit and a rare degree of sensitivity. Beneath the gentle laughs, this show still has real bite.

There’s an economic storyline, there’s a racial storyline, there’s an immigrant storyline, and on top of that, there’s leprechaun magic.

That’s four major ways to go wrong and yet not one false step is ever taken.

The cheap Celtic sentiment is kept to a minimum, thanks to the watchful eyes of the savvy actors (Norton in particular) who are happy to undercut schmaltz the moment it appears. The show’s English director, Warren Carlyle, who has eight West End musicals under his belt, wisely allows Norton to become what he should be — the show’s breakout star.

Resisting every temptation to play an Irish stereotype, Norton’s a marvel in the title role of Finian, a lovable Irish rogue taking a shortcut to Easy Street. Onstage, his unexpectedly subtle performance wisely lets the paternal bond between himself and his daughter Sharon (Baldwin) become the emotional center of the show.

You’ll be delighted and moved by Norton’s Tony-worthy performance as this irresistibly silly musical sets out in search of that thing we’re all looking for – a bit of peace and happiness.

You’ll find it at the end of "Finian’s Rainbow."

"Finian’s Rainbow" plays at the Saint James Theatre, 246 W. 44 St. For tickets, call (212) 239-6262 or go to TeleCharge.