Diana Vishneva and Angel Corella opened American Ballet Theatre’s weeklong run of “Romeo and Juliet” on Monday night, and despite Ms. Vishneva’s masterful Juliet, theirs was not a love story for the ages. These two dancers are a potentially interesting partnership, but the elements that make that union interesting — and fragile, at the same time — are dissimilar temperaments and training. Last year in “Giselle,” their performance seemed disjunctive, but last month they were much more in tune. The customarily boyish Mr. Corella was convincing as an aristocrat and as a remorseful tragic hero. He expunged some of the literalisms that intruded on his Albrecht, and this brought him and Ms. Vishneva together more felicitously. Likewise, Mr. Corella’s Aminta in “Sylvia,” last week opposite Paloma Herrera was so in key with Ashton’s ballet that one could only ask why he doesn’t dance with an equivalent degree of artistry all the time.

Part of the problem is Mr. Corella’s audience. Legions of his fans ask of him no more than he dance energetically and flash his smile. Trouble is, he looks more mature and more handsome when he doesn’t grin.Therefore, to perfect and expand his artistry he must perhaps be willing to some degree to disappoint his fans’ expectations.

But ABT’s “Romeo” is at times uncommonly good theater, bolstered by the miming of the character portrayals and by the cohesive, engaged tensions that animate confrontations in Juliet’s bedroom and at the ball. The dead spots in the ballet that have always given it a degree of tedium seemed to have vanished.

Ms. Vishneva’s Juliet achieved a wonderful rapprochement between the let-it-all-hang-out-ism of MacMillan’s assertive heroine and the more restrained key of what she dances in Russia, the 1940 Leonid Lavrovsky production. Ms. Vishneva was lively, frisky, and impulsive in her early scenes, and she was funny, too, putting her mother and nurse off the scent of her ballroom flirtation by pretending that she wasn’t feeling well.

One of the reasons that Mr. Corella’s Romeo didn’t match his Albrecht or Aminta is probably that those roles are more fully realized character than Romeo (as conceived by MacMillan). Romeo is in a sense the least interesting characters in the ballet. There are a few moments that establish him as dreamer or poet in Act I, when he sits downstage and ruminates; primarily he is playboy, lover, and fighter, but above all he is childish.

Mr. Corella was suitably grave throughout Act III; he was no longer smiling, but neither was he particularly forceful. Romeo isn’t seen much in Act III, but from the top of the act, in their bedroom adagio before Romeo flees Verona, it was clear that Ms.Vishneva was now going to take the law, and the ballet, into her hands. From there on, it was the ballerina’s show, as it inevitably must be in MacMillan’s production, although the matrix of supporting players expertly wove the web that sealed her doom.

Throughout this act, Ms. Vishneva tied together all the multiple strands of the character, the shifting moods and impulses of her heroine. Bidding farewell to Romeo, she rent the air with protest, pain, and fury that she vented on him, as well as on the forces of circumstance and civil society that were driving them apart. In his arms she collapsed to the ground with abandon, but then she sent Romeo on his way — assuring him that it was okay, she would be fine, and so prepossessing was she that for a moment we almost believed her. She allowed us to glimpse the child she had been, as she threw herself at the feet of Frederick Franklin’s Friar Laurence, but there was no compromising her resolve and her independence.

As Lady Capulet,Veronika Part was a Botticelli come to life, an incomparably elegant paragon whose self-possession didn’t lessen her human eloquence. As Lord Capulet, Victor Barbee was attractively weathered, a Veronese oligarch not to be trifled with, but he never resorted to bombast. The circumferences of Juliet’s home life were well described by Susan Jones’s Nurse and David Hallberg’s Paris. Maria Bystrova as Rosaline and Jennifer Alexander’s Lady Montague were striking figures, and Gennady Saveliev’s Tybalt was as territorial and proprietary as anyone could ask for.

I had mixed feelings about both Herman Cornejo’s Mercutio and Sascha Radetsky’s Benvolio. It almost goes without saying that Mr. Cornejo flew through the air effortlessly, but his death scene could have been invested with more symbolic value. The fact that Mercutio remains heedless and irrepressible almost to the point of his death at the end of Act II is all the more reason for his death to portend the catastrophes to follow. On the other hand, Mr. Cornejo never attempted to violate ensemble propriety by making the role into a self-serving turn, and that was admirable.

Mr. Radetsky is too honest a performer to not be flummoxed by the relentlessly zany, hyperrealistic cavorting he’s given here, and as he demonstrated all season, he has too much artistic potential not to seem wasted in a one-dimensional role. But he certainly justified his inclusion in the opening night cast and added substance to it.

What makes “Romeo” more successful than many of Mr. MacMillan’s later three-act ballets is that the classical dancing is not purely and pristinely classical, and thus does not seem so incongruous when placed next to the realistic details that fill his ballet. Monday night’s cast made it easy to surrender to the ballet.

Until July 15 (Lincoln Center, 212-362-6000).