Rene Barbera and Eglise Gutierrez in Washington Concert Opera's production of Bellini's “La Sonnambula.” (Don Lassell)

The Washington Concert Opera probably didn’t mean to show up the Washington National Opera when it scheduled Bellini’s “La Sonnambula” on Sunday afternoon at Lisner Auditorium, the day after the WNO opened its season with Donizetti’s “Anna Bolena.”

It’s true the two operas have a lot in common. Both are staples of the bel canto repertoire; both premiered in the 1830-31 season at the same theater in Milan (“Bolena” in December, “Sonnambula” in March). Their librettos were written by the same poet, Felice Romani, and the leads were first played by the same singers, the soprano Giuditta Pasta and the tenor Giovanni Battista Rubini.

But though the similarities could have been foreseen, it’s doubtful anyone anticipated that the WCO’s cast, point for point, would be so much better than the WNO’s.

In fairness, “Sonnambula” is an easier opera to stage. “Anna Bolena” was a breakthrough opera for Donizetti, with big, passionate, dramatic roles; “Sonnambula” has a soap-bubble plot that doesn’t bear much scrutiny at all. (Boy and girl are in love; girl wanders into count’s bedroom at night; boy decides she’s cheated on him; oh, wait, girl is a sleepwalker! All is forgiven!) What it does have is glorious music: Bellini’s melodic gift made him one of the most beloved composers of the 19th century (Richard Wagner, for one, was a big fan). The title role isn’t exactly easy, but it’s easier than Anna Bolena, and the auxiliary roles get pretty arias that are less vocally taxing than “Anna Bolena’s” big duets.

Both the WCO and the WNO fielded strong sopranos with international careers but with voices so different it’s hard to believe the same singer originally sang both roles. Where Sondra Radvanovsky showed a big, warm, clarion voice as Anna Bolena, Eglise Gutierrez, who sang Amina in “La Sonnambula,” was all about floating pianissimos, gentle clouds of sound, the dewdrops-and-roses school of bel canto, matching her diaphanous pink dress. Her performance was gorgeous, apart from a few times when she failed to get a high note out — possibly due to fatigue undermining her breath support, and never at a real climax.

Where the WCO excelled was at putting together a cast to match its soprano. Elvino, the tenor lead, is a bit of a loser — everyone in Switzerland thinks his girlfriend is a model of purity, and he still finds a way to be jealous? — but Rene Barbera found the character’s inner appeal, with an assured, warm voice, lusty high Cs, and a stage presence evoking familiar tenor tropes (the solid body, the dark beard, the sense of humor). As Lisa, who keeps the local inn and has designs on Elvino herself, the soprano Maureen McKay showed considerable coloratura chops.

Ben Wager was a slightly weaker link as Count Rodolfo, who turns up in his childhood home with such a flimsy incognito that even the credulous Swiss villagers of the chorus need only a couple of scenes to figure out who he is. His voice was pleasant but imprecise, possibly because the role lies awfully low for someone who bills himself as a baritone. Madeleine Grey, as Amina’s foster mother, and Matthew Osifchin, as Lisa’s would-be lover, were both adequate if not outstanding. But casting the throwaway role of the Notary with a tenor as substantial as Rolando Sanz amounts to a kind of showing off: Few companies can field even one good tenor, let alone two.

One reason the whole thing sparkled is that conductor Antony Walker, the WCO’s music director, approaches music with the kind of spark and verve that made some of us fall in love with it in the first place. He got a kind of precision out of the WCO orchestra that the WNO, on opening night, couldn’t quite muster. He also actively supported the singers, or got out of their way — for instance, at the end of Gutierrez’s and Barbera’s exquisite duet at the end of the first scene, in which they engage in a series of a capella vocal arabesques simply to say good night.

This season, the WCO returns to the bel canto canon from which it has strayed in recent seasons. Its other performance this season is another of Donizetti’s Tudor operas, “Maria Stuarda.” Of course, it can’t really compete with the WNO, which offers a full season of fully staged operas. But — as it did in 2008 when it put up Donizetti’s “Maria Padilla” against the WNO’s “Lucrezia Borgia” — it can sure remind the other company how it can be done.