The only thing more dangerous than confronting one’s pipe dreams, it would appear, is maintaining them. In Eugene O’Neill’s towering “The Iceman Cometh,” a charismatic killer drags more than a dozen fellow souses off their barstools and into the shocking light of reality, all but crushing them in the process. In O’Neill’s more modestly scaled “A Touch of the Poet,” receiving a pungent if lopsided revival at the Roundabout’s Studio 54 space, reality is the only thing that can save its leading man after a lifetime of evasions.

Director Doug Hughes, who has recently verged on overexposure with “The Paris Letter” and “A Naked Girl on the Appian Way,” regains his footing here. He relies heavily on the brooding gifts of Gabriel Byrne, who finds the ludicrous as well as the tragic depths in the striving, vindictive Cornelius (Con) Melody. An Irishman of humble origins, Con has staked his entire existence on convincing 1820s Boston that he’s actually a gentleman fallen temporarily on hard times. His preening vanity, however, poses a dire threat to the happiness of his family – and possibly to his life.

All forelocks and craggy grandeur, Con is defined by his sodden pride. He can’t afford the family’s groceries but makes sure his thoroughbred mare is cared for. Con does nothing all day but drink and pontificate, yet he hires a barkeep so as not to dirty his hands. The only clean thing in his dingy tavern – Santo Loquasto’s brooding set practically reeks of sweat and cigarette smoke – is a gleaming mirror over the mantel, the better for him to test his various profiles and declaim verse by Lord Byron. (“I stood among them, but not of them” is a particular favorite.) He heaps contempt on his unassimilated wife, Nora (Dearbhla Molloy), for reminding him where he comes from.

No wonder their poised teenage daughter, Sara (Emily Bergl) – whose breeding has placed her somewhere between Con’s lofty airs and Nora’s squalor – has no idea whom to emulate. She bristles at her mother’s naive protestations of love and looming Catholic guilt (Con married her to make an honest woman of her, and won’t let her forget it) almost as much as she does her father’s pathetic grandiosity. This ambivalence reaches a boiling point when she lunges at a chance to rise above their station by courting a wealthy young (unseen) Yankee who has been convalescing above the tavern.

In fact, all three of the Melodys grapple with a constant back-and-forth of roiling emotions. O’Neill had a touch of the pedant to him, you see, subjecting his characters to a dizzying series of 180-degree emotional lurches outlined in explicit stage directions.In the space of one seven-sentence speech, an initially “pleased” Con goes on to speak “with Byronic gloom,” then switches to “gallantly” eight words later, and finally addresses Nora “scornfully.” This monologue lasts about 20 seconds, and nearly every speech in the play is similarly mercurial.

While plenty of playwrights include extensive stage directions, it’s up to the director to follow them or ignore them (usually the latter). But O’Neill’s dialogue makes no sense if these whiplash changes aren’t adhered to very closely, so Mr. Hughes and his cast have no choice but to throw themselves into the emotional riptide.

It is precisely in these vacillations, particularly Sara’s, that the production’s weak link becomes clear. Con is tugged between his facade and his true nature. Nora is tugged between shame at their circumstances and love for her dashing husband. And Sara? As written, her loyalties constantly shift between her pathetically grand father and her banged-up but proud mother: She sees right through Con, but she also sees the effect he has on others and his potential: “Oh, Father, why can’t you ever be the thing you can seem to be?” However, Ms. Bergl emphasizes Sara’s contempt for Con and downplays her envy of him. As a result, the father-daughter conflicts lack the added punch of Sara hating most in Con what she sees – and, to some degree, aspires to – in herself.

Mr. Byrne also flags in these scenes: The pace during their confrontations stays resolutely on the slow side,and he misses the casual sadism of Con’s Act III speech about her prospects as a bride. These missed connections are hardly enough to derail O’Neill’s mounting tension, and Ms. Bergl does do a beautiful job of modifying her appearance (her accent, yes, but also her carriage and demeanor) as her lowerclass roots poke through. But the battle over Sara’s identity is too one-sided to be compelling.

Except for this imbalance, “Poet” makes terrific use of Mr. Byrne, whose last turn on Broadway was as the plainly autobiographical James Tyrone Jr. in O’Neill’s “A Moon for the Misbegotten.” (He’s in good company: Jason Robards, the supreme O’Neill interpreter of our time, also tackled both of those roles on Broadway.And Mr. Byrne physically fits the bill as O’Neill’s “embittered Byronic hero”Con far better than Robards ever could.) With his artfully extended fingers and his gnawing, mortified soul, his Con is detestable, poignant, and debonair all at once.

Nora’s feelings for Con are as clear as Sara’s are complicated. Ms. Molloy paints with heartbreaking clarity the pride she feels in him and a refusal to see him for what he really is.”It’s when you don’t give a thought for all the if’s and want-to’s in the world! … That’s love, and I’m proud I’ve known the great sorrow and joy of it!” Nora exclaims to Sara, and Ms. Molloy’s interpretation of this exhausted but still vibrant woman makes both of those extremes painfully apparent.

Mr. Hughes further cements his credentials as an actor’s director with his expert use of the supporting cast. Byron Jennings oozes dissolute camaraderie as one of Con’s fellow veterans of the Napoleonic Wars. (It’s the anniversary of the Duke of Wellington’s victory at Talavera, which inspires Con to change into his splendid scarlet uniform, also designed by Mr. Loquasto.) John Horton and especially Kathryn Meisle excel as the two Yankees drawn reluctantly into the Melody family’s travails; their characters, the Yankee suitor’s family lawyer and mother, wear with consummate ease the condescending certitude that Con has affected so painstakingly,making his efforts look even sweatier and more fruitless.

With top-flight revivals of “Misbegotten,” “Iceman,” and “Long Day’s Journey Into Night” reaching Broadway in recent years, it’s time to poke around at O’Neill’s B-list. Mr. Hughes’s lucid work here may not elevate “A Touch of the Poet” onto that upper stratum, but like David Leveaux did with “Anna Christie” in 1993, he has stoked the embers of passion and regret, of bravado and shame, that smolder in every mature work by America’s finest playwright.

Until January 29 (254 W. 54th Street, between Broadway and Eighth Avenue, 212-719-1300).