Technically it is impossible to steal the show when you are already the main character. But somehow that's what baritone Mark Delavan did with his brilliantly funny portrayal of Sir John Falstaff in the Pittsburgh Opera's production of Verdi's "Falstaff." A commanding presence vocally and visually in the production that opened Saturday night at the Benedum Center, you didn't want Delavan to leave the stage.

With a booming and dark-colored voice that never sounded taxed in the least as he rolled through the difficult part combined with a goofiness I found positively infectious, he created an unforgettable interpretation of the lusty, aging knight taken from Shakespeare.

Like Falstaff in front of a roast quail and mug of mulled wine, Delavan devoured the difficult and varied vocal line with gusto. The American's singing harbored that inner intensity crucial to the Verdi sound, highlighted by those sforzando outbursts of anger and excitement that punctuate the role. It was easy to hear why Delavan has recently made the move to the steely-cord role of Wotan, the ruler of the gods in Wagner's "Ring of the Nibelungs," which he has begun at San Francisco Opera.

But Delavan's embodiment -- make that em-"body"-ment -- of the "enormous" knight was truly something to behold. His physical presence on stage captured the power of this former warrior and emphasized just how delusional he is at this late point in his "career." It also set up the tall and fat-suited character as straight man to his own slapstick. Whether it was a vain Falstaff powdered for his imagined trysts with Alice Ford (Veronica Villarroel) and Meg Page (Katherine Drago) or Sir John Falsetto imagining how easy women fall for him, Delavan's comedy had a lovely quirkiness. From his scowling denouncement of honor to the belly bump he did with Master Ford (Stephen Powell) at the finale, Delavan expanded upon librettist Arrigo Boito's ideas instead of just following them. He was over-confidence personified and made the pranks played on Sir John fully enjoyable and warranted.

The gender-war plot of the comic opera favors the women, but the cast was the other way around. Powell was spectacular as Ford, with a stout voice that matched Delavan's. Doug Jones' Bardolfo was a hilarious mix of cowardice and false bravado. His companion Pistola was another Kevin Glavin special. The basso buffo made his 37th appearance with the Pittsburgh Opera and I still can't get enough of the Pittsburgh native's ability to move such huge gestures with such quickness and timing, not to mention a gloriously broad timbre.

Fenton was well cast in the person of James Flora, who held his lyrical tenor voice back to keep in character of the young lover, and Joseph Gaines was a nasty Dr. Caius.

With the women, it was not a matter of acting in this production ably directed by Paula Williams, but of simply not equaling the men in vocal prowess. It was most obvious in the ensemble work, but Villarroel, smashing as Butterfly a few years back, didn't carry the energy and support in her voice needed to be Falstaff's worthy opponent. She was convincing in the part, as were Katherine Drago (Meg Page) and especially the expressive Lindsay Ammann (Mistress Quickly), but they were simply outmatched as a group. Shannon Kessler Dooley was an appropriately fawning and alluring Nannetta, portraying her with a light and airy treatment.

Stuck in the middle of all of this craziness was another Delavan, Matthew. Mark's son played the silent role of Robin the page. It's usually a small part, but Williams put him in nearly every scene and the 9-year-old responded with flair and some sharp comic timing.

For what would be his final opera, Verdi created an exceptionally lively orchestral score that skilled conductor Antony Walker could not quite muster from his pit ensemble. Again, energy is the key here, and it just didn't come forth, although the horns and woodwinds were well-represented at times. The traditional scenery from the Canadian Opera Company was fitting and spacious, but for some reason it took quite long to change in between scenes.

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